ASME B18.21.1 pdf download Washers: Helical Spring-Lock, Tooth Lock, and Plain Washers (Inch Series)
1.8 Lot For all inspections referenced in this Standard, the lot shall consist of all washers of one type, grade, style, finish, and size fabricated by the same production pro- cess from the same heat number of metal as provided by the metal manufacturer, and submitted for inspection and testing at the same time. The maximum lot size shall be restricted to one shift of production.
1.8.1 Unless otherwise specified by the purchaser, unhardened plain washers (see para. 1.3.3) do not require lot control or heat control and are not subject to the maximum lot size requirement. NOTE: It is common to produce unhardened plain washers from scrap steel that does not normally have material heat traceability.
1.9 Inspection and Quality Assurance Unless otherwise specified, acceptability of this Standard shall be evaluated in accordance with ASME B18.18.2.
2 GENERAL DATA FOR HELICAL SPRING-LOCK WASHERS
2.1 Application: Helical Spring-Lock Washers The helical spring-lock washers covered in this Standard are intended for general applications. Helical spring-lock washers compensate for developed loose- ness between component parts of an assembly, and pro- vide a hardened bearing surface.
2.2 Dimensions: Helical Spring-Lock Washers The dimensions of regular, extra duty, and high-collar helical spring-lock washers shall be specified in Tables 1 through 4. Selection should be made from the regular, heavy, extra duty, or high-collar series in Tables 1, 2, 3, and 4, respectively, to suit design requirements.
2.3 Material and Hardness: Helical Spring-Lock Washers
2.3.1 Material Composition: Helical Spring-Lock Washers. Washers shall be made frommaterial meeting the chemical composition requirements of one of the following standards:
(a) Carbon Steel. SAE J403 1055–1065 (UNS G10550– G10650).
(b) Boron Steel. SAE J411 10B55–10B65.
(c) Stainless Steel. SAE J405 302–305 (UNS S30200– S30500) or SAE J405 316 (UNS S31600).
(d) Aluminum Alloy. ASTM B 211, Alloy 7075 (UNS A97075).
(e) Phosphor-Bronze. ASTM B 159, Copper Alloy No. 510 (UNS C51000).
(f) Silicon-Bronze. ASTM B 99, Copper Alloy No. 651 or 655 (UNS C65100 or C65500).
(g) Nickel-Copper-Aluminum. Federal Specification QQ-N-286 (UNS N05500).
(h) Alloy Steel. SAE J404 4037 (UNS G40370) or other alloy steel having at least 0.35% carbon. Other materials and grades shall be as agreed upon by the supplier and purchaser.
2.3.2 Hardness: Helical Spring-Lock Washers. All washers shall be prepared for checking the material hardness by cold (water) grinding or filing the sides sufficiently flat and parallel to ensure correct readings. If applicable, be sure to remove the decarburized or plated surface. If the size or shape of the washer does not allow flat grinding, the washer may be sectioned, mounted, and tested using micro-hardness. During these operations, care shall be exercised to prevent the surface temperature ofthe washer from exceeding 250°F. Hardness requirements applicable to washers of the respective materials shall be as follows. Refer to ASTM E 140 for hardness conversion.
(a) Carbon Steel. 38 HRC to 46 HRC,372HVto 458 HV.
(b) Boron Steel. 38 HRC to 46 HRC, 372 HV to 458 HV.
(c) Stainless Steel. 35 HRC to 43 HRC, forlock washers up to and including 5 ⁄ 8 in., for larger sizes 32 HRC to 43 HRC, 318 HV to 423 HV. (d) Aluminum Alloy. 75 HRB to 97 HRB, 137 HV to 222 HV.
(e) Phosphor-Bronze. 90 min. HRB, 185 min. HV, or equivalent.
(f) Silicon-Bronze. 90 min. HRB, 185 min. HV, or equivalent.
(g) Nickel-Copper-Aluminum. 33 HRC to 40 HRC, 327 HV to 392 HV.
(h) Alloy Steel. 38 HRC to 46 HRC, 372 HV to 458 HV. 2.3.3 Decarburization: Helical Spring-Lock Wash- ers. Carbon steel-, boron steel-, and alloy steel-lock washers shall meet the limits for decarburization shown in Table 5. The method of testing for decarburization limits shall conform with SAE J419.
2.4 Designation: Helical Spring-Lock Washers Nominal washer sizes are intended for use with com- parable nominal screw or nut sizes. Fasteners conforming to this Standard shall be designated by the following data and sequence shown, or optionally by the code system in ASME B18.24:
(a) product name and style, where applicable
(b) ASME document number (ASME B18.21.1)