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Heavy Nuts
heavy-nuts
Hex heads are manufactured by Robbins Mfg. Co. and nuts by Robbins Mfg. Co., Texas Bolt Co., and SPS-Non-ferrous. All hex heads are made of 304 stainless steel. Heads are marked with Robbins "R" trademark and "B8". Finished and heavy nuts are made to ASTM A194 specifications and stamped with manufacturer's trademark and "8" or "8M". Some finished nuts are also stamped "304" or "316".
Chemicals and physicals available showing compliance to ASTM specifications.
Chemical and physical reports available upon request at no charge.
Manufactured to MIL-S-1222H amend. 3 Type III, Style B and ASTM F467-93 by Robbins Manufacturing Co., Inc. /Asset/1163_Nickel-Copper-400-Heavy-Nuts.JPG
Heavy Square Nuts
(13)- Tops of Nuts. Tops of nuts shall be flat and chamfered or washer crowned. Diameter of the chamfer circle shall be equal to the maximum width across flats within a tolerance of minus 15 percent. The surface of chamfer may be slightly convex or rounded.
- Width Across Flats. Maximum width across flats shall not be exceeded. No transverse section through the nut between 25 and 75 percent of the actual nut thickness as measured from the bearing surface shall be less than the minimum width across flats.
- Bearing Surface. Bearing surface shall be perpendicular to the axis of the threaded hole within a tolerance of 3 deg for 1 in. nominal size nuts and smaller, and 2 deg for nuts larger than 1 in.
- True Position of Tapped Hole. The axis of tapped hole shall be located at true position with respect to the axis of nut body within a tolerance zone having a diameter equivalent to 10 percent of the maximum width across flats, regardless of feature size.
- Threads. Threads shall be Unified coarse thread series (UNC series), Class 2B, in accordance with ASME B1.1.
- Material. Unless otherwise specified, chemical and mechanical properties of steel nuts shall conform with Grade A of ASTM A563. Nuts of other materials such as corrosion resistant (stainless) steel, brass, bronze and aluminum alloys shall have properties as agreed upon between the manufacturer and purchaser. The properties for nuts of several grades of corrosion resistant steel alloys are covered in ASTM F594, and of several nonferrous materials in ASTM F467.
- Nominal Size. Where specifying nominal size in decimals, zeros preceding the decimal and in the fourth decimal place shall be omitted.
Heavy Hex Flat Nuts
(14)- Unification. Bold type indicates products unified dimensionally with British and Canadian standards.
- Smaller Sizes. For sizes 1/4 in. through 1 in., the nuts specified in Table are recommended.
- Tops of Nuts. Tops of nuts shall be flat and chamfered. Diameter of the chamfer circle shall be equal to the maximum width across flats within a tolerance of minus 15 percent. The length of chamfer at hex corners shall be from 5 to 15 percent of the basic thread diameter. The surface of chamfer may be slightly convex or rounded.
- Width Across Flats. Maximum width across flats shall not be exceeded. No transverse section through the nut between 25 and 75 percent of the actual nut thickness as measured from the bearing surface shall be less than the minimum width across flats. For milled-from-bar nuts, see statement in General Data pertaining to the nominal bar size to be used.
- Corner Fill. A rounding or lack of fill at junction of hex corners with chamfer shall be permissible provided the width across corners is within specified limits at and beyond a distance equal to 17.5 percent of the basic thread diameter from the chamfered face.
- Bearing Surface. Bearing surface shall be flat and perpendicular to the axis of the threaded hole within a tolerance of 2 deg.
- True Position of Tapped Hole. The axis of tapped hole shall be located at true position with respect to the axis of nut body within a tolerance zone having a diameter equivalent to 4 percent of the maximum width across flats for 1-1/2 in. nominal size nuts or smaller, and 6 percent of the maximum width across flats for nuts larger than 1-1/2 in., regardless of feature size.
- Threads. Threads shall be Unified coarse thread series (UNC series), Class 2B, in accordance with ASME B1 .1.
- Material. Unless otherwise specified, chemical and mechanical properties of steel nuts shall conform with Grade A of ASTM A563. Nuts of other materials such as corrosion resistant (stainless) steel, brass, bronze and aluminum alloys shall have properties as agreed upon between the manufacturer and purchaser. The properties for nuts of several grades of corrosion resistant steel alloys are covered in ASTM F594, and of several nonferrous materials in ASTM F467.
- Nominal Size. Where specifying nominal size in decimals, zeros preceding the decimal and in the fourth decimal place shall be omitted.
Heavy Hex Flat Jam Nuts
(14)- Unification. Bold type indicates products unified dimensionally with British and Canadian standards.
- Smaller Sizes. For sizes 1/4 in. through 1 in., the nuts specified in Table are recommended.
- Tops of Nuts. Tops of nuts shall be flat and chamfered. Diameter of the chamfer circle shall be equal to the maximum width across flats within a tolerance of minus 15 percent. The length of chamfer at hex corners shall be from 5 to 15 percent of the basic thread diameter. The surface of chamfer may be slightly convex or rounded.
- Width Across Flats. Maximum width across flats shall not be exceeded. No transverse section through the nut between 25 and 75 percent of the actual nut thickness as measured from the bearing surface shall be less than the minimum width across flats. For milled-from-bar nuts, see statement in General Data pertaining to the nominal bar size to be used.
- Corner Fill. A rounding or lack of fill at junction of hex corners with chamfer shall be permissible provided the width across corners is within specified limits at and beyond a distance equal to 17.5 percent of the basic thread diameter from the chamfered face.
- Bearing Surface. Bearing surface shall be flat and perpendicular to the axis of the threaded hole within a tolerance of 2 deg.
- True Position of Tapped Hole. The axis of tapped hole shall be located at true position with respect to the axis of nut body within a tolerance zone having a diameter equivalent to 4 percent of the maximum width across flats for 1-1/2 in. nominal size nuts or smaller, and 6 percent of the maximum width across flats for nuts larger than 1-1/2 in., regardless of feature size.
- Threads. Threads shall be Unified coarse thread series (UNC series), Class 2B, in accordance with ASME B1 .1.
- Material. Unless otherwise specified, chemical and mechanical properties of steel nuts shall conform with Grade A of ASTM A563. Nuts of other materials such as corrosion resistant (stainless) steel, brass, bronze and aluminum alloys shall have properties as agreed upon between the manufacturer and purchaser. The properties for nuts of several grades of corrosion resistant steel alloys are covered in ASTM F594, and of several nonferrous materials in ASTM F467.
- Nominal Size. Where specifying nominal size in decimals, zeros preceding the decimal and in the fourth decimal place shall be omitted.
Heavy Hex Nuts for Use with Structural Bolts
(9)- Unification. Only the 9/16 size is not unified dimensionally with British and Canadian standards.
- Tops and Bearing Surfaces of Nuts. Nuts may be double chamfered or have washer faced bearing surface and chamfered top.
The of chamfer circle on double chamfered nuts and diameter of washer face shall be within the limits of the maximum width across flats and 95% of the minimum width across flats.
The tops of washer faced nuts shall be flat and the diameter of chamfer circle shall be equal to the maximum width across flats within a tolerance of -15%. The length of chamfer at hex corners shall be 5% to 15% of the basic thread diameter. The surface of chamfer may be slightly convex or rounded.
Bearing surfaces shall be flat and, unless otherwise specified, shall be perpendicular to the axis of the threaded hole within the total run out (FIM) tabulated for the respective nut size, type, and strength level. - Position of Hexagon to Tapped Hole. At maximum material condition, the axis of nut body shall be located at true position with respect to the axis of the tapped hole within a tolerance zone having a diameter equivalent to 4% of the maximum width across flats for 1-1/2" nominal size nuts or smaller.
- Countersink. Tapped hole shall be countersunk on the bearing face or faces. The maximum countersink diameter shall be 1.08 times the thread basic (nominal) major diameter. No part of the threaded portion shall project beyond the bearing surface.
- Corner Fill. A rounding or lack of fill at junction of hex corners with chamfer shall be permissible provided the width across corners is within specified limits at and beyond a distance equal to 17.5% of the basic thread diameter from the chamfered faces.
- Width Across Flats. Maximum width across flats shall not be exceeded.
Grade 8, 8M 316 Finished & Heavy Nuts
(23) Made in U.S.AHex heads are manufactured by Robbins Mfg. Co. and nuts by Robbins Mfg. Co., Texas Bolt Co., and SPS-Non-ferrous. All hex heads are made of 304 stainless steel. Heads are marked with Robbins "R" trademark and "B8". Finished and heavy nuts are made to ASTM A194 specifications and stamped with manufacturer's trademark and "8" or "8M". Some finished nuts are also stamped "304" or "316".
Chemicals and physicals available showing compliance to ASTM specifications.
- Material to ASTM A193 grade B8 specification and to ASTM A194 grade 8/8M specification.
- Dimensions on ANSI/ASME B18.2.2, threads to ANSI/ASME B1.1.
- Manufacturing process, mechanical properties, hardness, and marking to ASTM A193 and ASTM A194.
- Testing to ASTM A370 specification.
Nickel Copper 400 Heavy Nuts
(3) Stamped with Mfr. ID plus "NC" and "F467U"Chemical and physical reports available upon request at no charge.
Manufactured to MIL-S-1222H amend. 3 Type III, Style B and ASTM F467-93 by Robbins Manufacturing Co., Inc. /Asset/1163_Nickel-Copper-400-Heavy-Nuts.JPG
