Specifications Dimensions Assembled Depth (in inches) 2. The heads had a clearance of 3–8 µm so that each convex dovetail slide was slightly larger than its corresponding concave dovetail groove. The first toolpath is made for taking off material with a 1/4 bit (I chose to use a down-cut bit for a cleaner result). Mossberg’s tip-off concept spawned some new ideas, such as this Bushnell scope with a dovetail rail that mirrors a . 376 through . O-Ring Size Charts O-ring, x-ring and square ring size charts. MSC# 06451660 Mfr# 400. Dovetail and Half-Dovetail Grooves. Sight dovetail requirements: Front sight: . Spindle Speed: 14000 r. Engraving. 5 mm, 14. 25 Sealing Details / Elastomer seals O-ring tolerances ± 0. of an O-ring gland is mainly influenced by diameter of the mating surface of the rod or piston and bore. Ruger 77 (M-77) Rings. This document covers the basics of O-Ring sealing, elastomer properties, and dynamic and static design criteria. 53 - O-Ring Dovetail Groovers. 70 - Single End Split Blanks. 000 +. This recommended practice provides the design criteria for static elastomeric O-ring seals used specifically in engine and engine control systems. Dovetail grooves are used to hold the O-ring in place on a face seal groove during assembly and maintenance of equipment. e. 433". (fig. This can be easily achieved by taking a fly-cut on the surface prior to milling the groove. 005 clearance per side): Calculator Output Precision: decimal digits. The 3/8" Dovetail is a measurement at the bottom (narrowest) part of the Dovetail. 003. • The first is overfill from high volume caused by a very small gland. For more information contact:250" x 74° dovetail, cut ~. In milling the groove, a regular o-ring groove using the dimensions of “W” and “L” must be made first, then finished up with a dovetail cutter. Need space in groove to allow for volume swell, thermal expansion, and increasing width due to squeeze. The breakthrough dovetail clamps are design gives you the freedom to create your own tracks grooves using a dovetail router bit to clamp virtually anywhere. Product Dimensions : 10. 59 0. Making a dovetail oring groove is an annoying task on a good day at normal size scales. Groove Bore Piston Rod Figure 1-2: Basic Gland Introduction Figure 1-3: Gland and O-ring Seal. 070, . Includes (6) 1" track screws. • No critical torque on tightening, therefore unlikely to cause structural damage. O-Ring Face Seal Glands These dimensions are intended primarily for face type O-ring seals and low temperature applications. 157 0. 11. Try to keep the depth of the dovetail groove between 1/3 and 1/2 the thickness of the part. High Efficiency: The dovetail cutter has high grinding accuracy, it is mainly used for machining dovetail groove cutter. O-RING GLAND TYPES AND NOMENCLATURE Most static O-ring seals can be classified into one of the three arrangements shown below. The specifications and dimensions of some parts may not be fully covered. 8 μm Ra) dovetail gland and o-ring width and depth default recommendations dovetail gland and o-ring diameter default recommendations-005 0. Wood joints are typically. The American dovetail actually measures 12. Kalrez® O-Rings FFKM. Dividers: You can also use a compass, ruler, or calipers too. The three parts of SAE J1453 cover material, dimensional, and performance requirements of steel O-ring face seal (ORFS) connectors for tubing and the O-ring face seal interface and nut portion of hose stem assemblies for nominal tube diameters of. g. Create dovetail grooves that allow O-rings to flex without falling out of place. 275 of Y14. This is done by measuring the old sight, the sight cut and the new sight and making a plan to remove. Novak's will fit but it is recommended purchase of Novak for Kimber (because they are nearly but not precisely the same). Choose whether you are working with existing hardware or designing new hardware. The dovetail grooving inserts are intended to machine O-ring dovetail grooves with 66-degree undercut angles. It wouldn't make any difference complexity wise whether you were cutting a single or double dovetail groove. The design has proven beneficial in many applications but, according to Parker engineers, is an expensive groove to machine and should only be used when absolutely necessary. Boss seal The groove dimensions are incorporated in the standard dimen-sions. Noted for its resistance to being pulled apart, also known as tensile strength, the dovetail joint is commonly used to join the sides of a drawer to. Test Indicator Mini Indicol Holder: Use with Dovetail & 5/32 in Indicators. Do not need a base as they attach directly into grooves in the receiver. KENAT: Regarding the taper in the plan view of your new sketch, consider the Fig 6-24, (p. ) and includes the Extended Sizes in the 400 Series. Also called a “tip off” mount, the dovetail rail allows the shooter to easily remove and replace mounted optics. Several alternative designs were considered before agreeing to adopt the dovetail groove. When compared to tools without drop-hole allowance, tools with drop-hole allowance have a much larger neck diameter-to-cutter diameter ratio. / ea. Weaver rails feature . Stand your piece up vertically on your work surface. 22’s receiver grooves. Surface Finish Static Grooves Straight-sided grooves are best to prevent extrusion or nibbling. 5M-1994)dimensioning method (again, linear, not diametral. 000 +. 122 0. Many fluids can cause an O-ring material to swell 10 or 20%. The second toolpath is designed for a 73° dovetail router bit. Note that the dovetail groove becomes rectangular when the base angle a = 90°. O-Ring Size AS568A-W Cross Section Nominal Actual L Gland Depth Squeeze % G Groove Width (To sharp corner) R R 1 004 through 050 1/16. of sizes from 5” I. 500". There were 20 samples of 360 L × 50 W × 24 H mm; dovetail, tongue and groove, halving, and dowel joints for each test. They both measure about the same width when measured at the same locations. Before plywood became common, tongue and groove boards were also used. 29 3. After selecting a material that fits your sealing application, you can continue by having the Size Selector calculate the O-ring dimensions and tolerances, considering even thermal expansion and volume swelling of the sealing element. The new Kensight adjustable designed for the 17. 063” to 1”. Secure material with ZERO interference. 139. Generally, these values can be adopted for other materials and material hardnesses, the groove depth may have to be adjusted. Surface Finish Static Grooves Straight-sided grooves are best to pre-vent extrusion or nibbling. Available in the most popular materials. Machine circular grooves onto the end of a workpiece. to 500” I. GROOVE 'N TURN® dovetail grooving inserts are used to machine O-ring dovetail grooves with 66° undercut angles. The design is optimized for strength by using an insert pair to generate the groove form. O-Ring Size AS568A-W Cross Section Nominal Actual L Gland Depth Squeeze % G Groove Width (To sharp corner) R R 1 004 through 050 1/16. Cut the 1/4" plywood bottom to size. 000000. For applications requiring more than two or three. Lay Out Tails. How. Square. Going to go into the right side of the jig, inside out. Make sure you set the Tail Depth correctly and copy the lines into the right place. Compare O-Ring Sizes USA AS568 Parker O-Ring Size Chart, X-Ring Square Ring Size Charts. Asking a dovetail cutter to plow through a hard slide cutting on a full 180-degree path is begging for an overheated and worn (or broken) cutter, a work-hardened slide and poor cut finish. Putting the angled face to the outside renders it useless for retaining the o-ring because the o-rings is pulled towards the. Table 3. The connectors are called tails and pins. A dovetail joint or simply dovetail is a joinery technique most commonly used in woodworking joinery (carpentry), including furniture, cabinets, [1] log buildings, and traditional timber framing. Unequal flute spacing and irregular flutes ensures stable machining of difficult-to-cut materials and higher efficiency. The dovetail creates a strong and secure area for clamping, while. 490" Thru 44mm 30MM X-High . Single flute carbide O-Ring form tools for lathe applications. In fact, you can even get varying distances between grooves within the same rail. 5” (1. 42, lists SAE recommended dimensions for dovetail glands by ascending AS-568* numbers. 375 No Drop Hole Provision ID 4185- Your Price: $119. Index Table of Contents. 2 W Cross Section Nominal Actual L Gland Depth Squeeze Actual % G Groove Width R Groove Liquids Radius Vacuum and Gases 004 through 050 1/16. This groove can either be extruded, or machined using a special dovetail cutter which is available from Spira. Their extreme hardness means they are brittle, so a highly rigid setup, such as a CNC machine, is necessary to prevent. Step Down: 4mm per pass (3 passes) Feed Rate: 45mm/sec. The ERIKS O-ring design calculator features the calculation of: • o-ring dimensions for the use in a specific. Finally I realized just fit the scope ring, finger tight onto the rail, slide it off and measure the dovetail width on the scope ring! Measuring the RWS dovetails were 9. Parker Hannifin O-Ring & Engineered Seals 2360 Palumbo Drive Lexington, KY 40509 Ph: 859-269-2351 Fax: 859-335-5128 oesmailbox@parker. Tolerances. For instance, on the aforementioned 18" x 12" box, the bottom should be cut to a size of 17" x. Wood joints are typically. by Apollo » Sat Sep 16, 2017 12:12 am. Metric o-ring groove dimensions are listed for the most common metric cross-sections with and without backup rings. O-Ring Cross-Section. Half Dovetail Groove Detail For dovetail grooves, match the centerline of the groove with the centerline of the O-ring. Parts. See the Dovetail Groove Cutter data sheet for more information (page 36). When machining this groove, a standard o-ring groove must be machined first. After entering the groove dimensions, enter the application parameters as well as the o-ring size or dimensions. Parker O-Ring Handbook 5700 Handbook Introduction 1-3 Seals Build With The Best!The O-ring inner diameter (ID) should also stretch approximately 5% over your groove or gland. has a geometry that won't allow for thermal expansion of the ring at 350 F. This type of dovetail cutter tip is useful for machining female semicircle grooves of radii. 75 Inch Fixtures Dovetail Fixtures. e. Cut the grooves in the other three pieces of stock in precisely the same manner. e. NOT novak) sight that is falling out and I want to replace it with a new rear sight. 5 mm. » FilterSeals® Innovative FilterSeals® are custom designed as a combination elastomer and fabric device that operates as both a seal and a filter. Rounded-Edge Square. should be a normal 3/8" / 9. For designing systems which contain internal pressure, like the example below, the groove's outside diameter (OD) is primary, and the groove's width then determines the inside diameter. Offered with a sharp corner, . A LEADING PROVIDER OF HIGH QUALITY O-RINGS, O-RING KITS & ACCESSORIES INSIDE DIAMETER (ID) CROSS SECTION (CS)Simply select the three segments you want to move and use the Move tool to place them as needed. Dovetail cutters are specialized tools for cutting a dovetail angled grooves into a workpiece and are used for fitting or joining parts. 070 0. , seal squeeze and groove volume to accommodate O-ring swell. Before you can install the sight in a sight cut & dovetail, you generally have to fit the sight to the sight cut & dovetail. Dovetail Insert Styles. O-ring in the smallest possible groove (i. 300 in. O-Seals. For standard O-ring grooves in the face and radial applications, we recommend 60-90% gland fill. 5” cube. 054. 10 1. Our custom KLICK Dovetail Router Bit is specifically designed to route the groove for the KLICK and sKLICK. Catalog excerpts. Exert versatile clamping pressure without interfering with the operation by containing the MATCHFIT Dovetail Clamp head arm within the dovetail groove. and in cross sections from . Remove the original dovetail plate of ASIAIR PRO. Hawke’s 30mm, 9-11mm Dovetail rings come in two sizes; medium and high. O-ring groove design is a key consideration in the o-ring selection process. • Encourages the shielding perfor-mance illustrated in the ShieldingDovetail seal Also here there is a metal to metal contact as long as the con-struction will not deform under system pressure. The variable names PISTON-TYPE SEAL FACE-TYPE. 070 0. 090, . Enter the GROOVE DIAMETER 4. Dovetail rails for detachable sights The SIG Sauer 200 STR has an 11 mm dovetail on the receiver for mounting a diopter rear sight or a scope sight, either directly or via a Picatinny rail adapter. for fluids. 005-. If you're asking about the sights on a Ruger 10/22, they're both, front and rear, 3/8" with a 60-degree angle. The MATCHFIT Dovetail Clamps add clever workholding into the jigs and accessories in your shop, with a clever redesign of the classic F-style clamp. 000 Groove Width G Gland Depth H External Pressure Diameter B Internal Pressure Diameter A AS-568* NumberVolume fill is the O-ring volume divided by the gland volume. However, that is not the only difference between the two dovetails. The variable names Piston-Type Seal Face-Type Seal Rod-Type. This document. Again this is the right side. Diamond Seals. -thick drawer front. O ring groove dimensions drawing. Enter the MINIMUM % COMPRESSION 8. 3 Advantages of O-Rings • They seal over a wide range of pressure, temperature and tolerance. Boss seal The groove dimensions are incorporated in the standard dimen-sions. The conditions considered to formulateGroove Challenges Dovetail and undercut grooves are typically designed to provide retention of traditional seal shapes. 5” (3. Static Male and Female O-ring Seal Design . O-Ring Metric Groove Design [PDF] Seal & Design Company Info. Aluminum, Brass, Bronze, Hardened Steel, Iron, Nickel, Plastic, Stainless Steel, Steel, Titanium, Tool Steel. Made of solid carbide, they are harder, stronger, and more wear resistant than high-speed steel and cobalt steel for the longest life and best finish on hard material. Made of solid carbide, they are harder, stronger, and more wear resistant than high-speed steel and cobalt steel for the longest life and best finish on hard material. Available in 1/2", 1/4", 12mm, and 8mm shank sizes. O-Ring Gland Types and Nomenclature Most static O-ring seals can be classified into one of the three arrangements shown below. The dovetail is a unique design which allows the installation of mounts on various rifles. The most common are: 11 mm, 12 mm, 13. Use the same groove dimensions as the standard o-ring groove discussed previously. O-ring in the smallest possible groove (i. A dovetail O-ring groove is a type of O-ring groove design that incorporates a dovetail-shaped cross-section. Polyurethane O-Rings. of Flutes Price AlTiN; HDG1/16. Features: O-Ring Dovetail Groovers Solid micrograin carbide ; For turning 24° o-ring dovetails; All shanks have two lockdown flats so you can flip the tool and cut both sides of the groove with the same tool. This is an excellent jig for routing the dovetail grooves on the MATCHFIT 360 Table. Because they can be expensive to machine, O-ring grooves should only be added when. Refer to the O-Ring Handbook or consult a Parker applications engineer for assistance in sizing O-rings to dovetail glands. Because of the difficulty in creating the groove and tight tolerances required, this type of seal application should only be used when necessary. . This paper covers the development and testing conducted to adopt the dovetail groove in the SAE standard. Dovetail Milling-Machine Vises. 001" increments Inserts can groove, turn/bore and generate profiles. 78 mm). Make it 1 ⁄ 8 " wide and nearly as deep as the dovetail groove. Browse from 17 included angles in both uncoated and AlTiN coated styles. A dovetail O-ring groove is a type of O-ring groove design that incorporates a dovetail-shaped cross-section. What are the dimensions of a dovetail slide? What size is the CZ 455 dovetail? CZ 455 comes equipped with an 11 mm dovetail. Groove Diameter ±. dimensions may be very difficult to assemble. We're proud to offer the world's largest inventory of readily-available and highly customized sealing solutions. D. C3 Gland Dimensions Dovetail Grooves, Inches O-ring Gland Depth. You can also minimize shielding degradation by placing the glue dots at fastener locations. 125” and . 1 degrees is 1/8. The joint pictured is a variation of a typical through – dovetail, in this case dressed up with a mitered corner. Simply route a groove anywhere you need using a 1/2”–14º dovetail router bit. Microjig Matchfit Dovetail Clamps are your go-to woodworking accessories for cutting composition materials, plywoods, hardwoods, and softwoods. It provides axial compression (face type) groove dimensions for aerospace metric O-ring sizes specified in MA2010. 11. Five degree A tongue and groove joint involves two complementary pieces: one with a protruding tongue and the other with a receptive groove. e Minimum full thread depth. 40 0. When machining this groove, a standard o-ring groove must be machined first. 070 . The dovetail’s profile includes a small neck diameter behind a larger end-cutting diameter. Convert Your Optic Scope Mount To Different Sizes. The geometry of the omega replica watches groove is important – the dimensions need to be specific because the o-ring is located in the groove. Something made in 2001. C-3 Gland Dimensions Dovetail Grooves, m e t rci W E F α R O-ring Groove Groove Side Wall Radius Cross Section Depth Width Angle mm E +-0,05 F +/-0,05 α +/-1° R 1 R 2 3,0 2,4 2,7 29 0,25 0,25. Press-In-Place Seals. The front ring is lower than the rear ring. Please contact Greene Tweed engineering for help or advice if required as some applications are difficult to optimize both at ambient and operating temperatures. Since a dovetail gland does not work with plastic components due to undercuts, nubs can be added to the groove wall to pinch the o-ring in isolated locations. The groove dimensions are incorporated in the standard dimensions. For a static male to female mating interface: a compression ratio of 18-25%. 030”, . Gaskets. Weaver Multi Slot (Photo: Weaver Optics) It’s not uncommon to see a Weaver rail with only a few slots and lots of space between. ) Flats for in-press servicing 120˚ (Typ. x = surface finish in µm Ra Fig. Item Dimensions LxWxH 4. The dovetail groove described in Design Charts 4-4 and 4-5 will serve this function. 32 cm; 680. Route dovetail grooves on a jig or work surface ; Use Dovetail Hardware to make stops and hold-downs that move freely, and tighten down anywhere you can route a groove. Sutibable allowances should be mde for higher swell compounds •For max. 013 to. Made of solid carbide, they are harder, stronger, and more wear resistant than high-speed steel and cobalt steel for the longest life and best finish on hard material. With any standard 1/2” 14-degree dovetail router bit, you can create your own clamp tracks anywhere you can route a dovetail groove. Step 2. How to dimension a groove with fits, detail view and symmetrical dimensioning using Siemens NX based on data of a circlip supplier. You can always vary the sizing on boxes where the overall height of the box is not intended to fit. MSRP. The 11 mm dovetail has a 60-degree angle, while the 3/8” dovetail has a 45-degree angle. Using the table above, determine the maximum recommended gland depth for your application. Like 15-30% based on service. 1-30 143 All the information in this documentation has been compiled with the greatest of care. Five. If this is the case, lack of space can damage the O-ring and affect the quality of sealing. Similar Sizes. 139 inch (3,53 mm) and bigger. Shop Manual Z-Axis Stages - Dovetail Groove, Rack & Pinion, Long Stroke, ZLWG Series from MISUMI. Once you find the right o-ring groove design you can easily order online from the world's largest. However, installing an O-ring into these grooves can be tricky without proper technique. Markez® O-Rings FFKM. Table B Static Axial Seal Gland Dimensions 4 Tolerance +. EZ-Lok Seals. Half Dovetail Groove. 005-. The three main types of standard groove designs are Industrial Static also called Radial, Industrial Reciprocating also called Dynamic, and Face Seals also called Axial or. Then, calculate the O-Ring groove diameter as follows: a. If you want to know more about o-ring groove dimensions and its functions, visit Allied Metrics. Burris 1" Rings Ruger 77 Extended Rear. Undercutting. PTFE o’rings in radially loaded closed grooves are generally not recommended, however if this is unavoidable, PTFE o’rings can be heated to around 100°C to. For rotary O-rings: a compression ratio of 0-10%. 002 for sizes 2-006 through 2-324 + . 050, . A schematic diagram of a dovetail, trapezoidal groove containing an O-ring is shown in Figure 1. 577" Thru 44mm 34MM XX-High 0. 5mm - horizontal bar. One piece features a recess that's half its thickness with a dovetail profile, while the mating piece has a corresponding extended dovetail shape. Dynamic applications: stretch a piston seal by up to 5% and compress a rod seal by up to 3%. When you need a dovetail groove longer than 6", use a tablesaw or a straight bit in your router to plow a groove down the center of the planned dovetail joint. Download the pdf to. This section calculates the equivalent circular groove dimensions, for use in the Seal Design Section, for a racetrack groove. Double-check that the rear edge is flush with your fence and the bottom is flush with the table itself before you begin cutting. While effective at retaining a seal, this method requires more assembly care and effort to preventA through dovetail joint displays interlocking pins and tails that extend through the full thickness of the adjoining pieces, visible from both sides. Groove Width: R1: R2: Cross Section (mm) Groove Depth E+/-0,05: F2 +/-0,05 (width to round. 3/8" dovetail grooves work best with very small and light scopes, which more easily follow the gun back under recoil. Quantity. If this taper is. Track with dovetail groove, Dovetail connector for concealed installation, aluminium Title of Asset 4434331. The calculator takes all relevant parameters into account like: O-Ring squeeze. A dovetail O-ring groove is a type of O-ring groove design that incorporates a dovetail-shaped cross-section. (male gland) Groove width Plug Dia. I put one of, his recoil Lugs, a new Volqt. By simply entering installation specifications for an application, it recommends O-Ring sizes, housing layout and. 210 . Learn more about Metric O-Ring Groove Design. Extractor & Firing Pin and a New, Green Mountain 20" barrel, on my Ruger 10-22. Their extreme hardness means they are brittle, so a highly rigid setup, such as a CNC machine, is necessary to prevent. of sizes from 5” I. Although dovetail rails come in a variety of sizes, the most common are 11mm and 3⁄8 inch (9. Precision coolant improves chip evacuation and decreases the risk of chip jamming in the groove, especially in deeper grooves. jimbod20, As far as the drawing specifications, if possible I think you'll find that a profile tolerance will much more reliably control the dimensions of a tapered groove like this. Dovetail and Half-Dovetail Grooves; Boss Seals; Failure Modes;. Standard dovetail-slide sets range from a couple inches to 20 in. e. The groove dimensions are incorporated in the standard dimensions. ) Leupold 1" Rings Ruger 77. For example, if the gable of a chest of drawers is 3/4″ thick, machine the dovetail groove between 1/4″ and 3/8″ deep. 275 . , at the hardware and O-ring tolerance stack-up) and the smallest possible O-ring in the largest possible groove. (male gland) Plug Dia. Excentricity info inner diameter stretch at inst (%)Start with the tails. - Table Saw - Router table - MATCHFIT Dovetail Router bit, or comparable 14º, 1/2” diameter dovetail router bit - 45 degree V-groove router bitThis article is from Issue 22 of Woodcraft Magazine. Furthermore, the O-ring groove has triangular, rectangular, or dovetail shapes. AS568B STANDARD O-RING GROOVE DESIGN. A side note on angles: In joinery, it is common to measure angles (other than square and 45 degrees), not in degrees, but as the ratio between the side and hypotenuse of a right triangle. So do the pins when viewing the end grain. 178 0. Select a size to buy standard and custom o-rings from the world's largest inventory network or custom orders can be made within a few weeks, typically without tooling fees. 15 small ± 0. D. Use face grooving tools with precision coolant supply even if the maximum coolant pressure in your machine is low (7‒10 bar (102‒145 psi)). Optimized for milling dovetail grooves into a part, Micro 100's solid carbide Dovetail Cutters are offered with 30°, 60°, and 90° included angles and in both uncoated and AlTiN coated styles. The composite GD&T frame I suggested above allows you to control the stuff that is really critical, and open up everything else. RWP-034SS, Stainless Steel, . 100, . 327 Thru 24mm 34MM High . Enter the diameter (D) (green line) of the dowels: Enter the angle (usually 60 degrees) of the dovetails: Enter the S Male (bottom red line) Measurement: Enter the height (H) (yellow line) of the dovetails: Enter the desired clearance (example: enter . On round top receiver narrow half lacks support below and rotates inward when tightened reducing. dxf. Installation steps Dovetail grooves are a great mechanism for holding O-rings in place. 005 9. These charts give dimensional information relating to standard and o-ring and dovetail o-ring grooves. Dovetail connector rail. This allows even complex parts to be completed in a single operation. Wouldn't slide onto the oddball rail at all! Fit the rings onto the oddball rail and slide 'em off, just eyeballing it was about 2mm. Surface Finish X groove top and bottom : for liquids X = 32 micro inches (0. 25 3. E. Surface Finish X groove top and bottom : for liquids X = 32 micro inches (0. Clamp the board down. 057 To. So, if you’re fairly new to woodworking, or you need to brush up on your skills, here’s your chance to master. 5M-1994)dimensioning method (again, linear, not. 002 Try to keep the depth of the dovetail groove between 1/3 and 1/2 the thickness of the part. For dovetail grooves, match the centerline of the groove with the centerline of the O-ring. Sizes and angles of sights can drive you nuts, because sight manufacturers don't like to give the actual dimensions of the sights they sell. 46 - Thread Relief Tools. Bellevue, WA 98005 USA Phone: (800) 562-8375 Fax: (425) 372-2001 info@aronson-campbell. With better heat and wear resistance than high-speed steel, these cobalt steel dovetail cutters run at higher speeds and provide better performance on hard material. As shown in above figure, an O-ring also gets compressed axially in a dovetail groove. Total indicator Reading between groove and adjacent bearing surface. It’s like an infinite supply of T-track without the cost of T-track. This paper focuses on analyzing mechanical behavior of dovetail joints with certain geometries and manufacturing imperfections subjected to different loadings.