ASTM F436 Round Washers - Precision Bolts

ASTM F436

Hardened Steel Washers

This specification covers the chemical, mechanical, and dimensional requirements for hardened steel washers for use with fasteners having nominal thread diameters of 1/2 through 4 inches. These washers are intended for general-purpose mechanical and structural use with bolts, nuts, studs, and other internally and externally threaded fasteners.

The types of washers covered here are: Type 1—washers made of carbon steel; and Type 3—washers made of weathering steel. Moreover, the styles of washers covered here are: circular washers, which are suitable for applications where sufficient space exists. Steels to be used to manufacture the washers shall be produced by the open-hearth, basic-oxygen, or electric-furnace process. Each type and style of washer shall be suitably sampled, and should conform to specified values of chemical composition, Rockwell hardness, inside and outside diameter, thickness, and clipped width.

Specifications

Dimensions & Markings

Bolt Sizes^D	A	B	C		Weight in Pounds Per 1000 Pieces
	Outside Diameter	Inside Diameter	Thickness
	Outside Diameter	Inside Diameter	Min	Max
1/2	1 1/16	17/32	0.097	0.177	20
5/8	1 5/16	11/16	0.122	0.177	35
3/4	1 15/32	13/16	0.122	0.177	41.20
7/8	1 3/4	15/16	0.136	0.177	71
1	2	1 1/16	0.136	0.177	93.80
1 1/8	2 1/4	1 3/16	0.136	0.177	120
1 1/4	2 1/2	1 3/8	0.136	0.177	144
1 3/8	2 3/4	1 1/2	0.136	0.177	174
1 1/2	3	1 5/8	0.136	0.177	208
1 5/8	3 1/4	1 3/4	0.178	0.28	311
1 3/4	3 3/8	1 7/8	0.178^B	0.28^B	328
1 7/8	3 1/2	2	0.178^B	0.28^B	345
2	3 3/4	2 1/8	0.178^C	0.28^C	398
2 1/4	4	2 3/8	0.24^C	0.34^C	568
2 1/2	4 1/2	2 5/8	0.24^C	0.34^C	734
2 3/4	5	2 7/8	0.24^C	0.34^C	921
3	5 1/2	3 1/8	0.24^C	0.34^C	1129
3 1/4	6	3 3/8	0.24^C	0.34^C	1350
3 1/2	6 1/2	3 5/8	0.24^C	0.34^C	1633
3 3/4	7	3 7/8	0.24^C	0.34^C	1880
4	7 1/2	4 1/8	0.24^C	0.34^C	2280

^B 3⁄16 in. nominal.
^C 1⁄4 in. nominal
^D"Bolt sizes", also known as "Nominal washer sizes" are intended for use with fasteners of the same nominal thread size.

Source: The table above is inspired by Table 2 from the ASTM F436 Standard that you can purchase on the ASTM Website

Product Marking

15.1 Washers shall be marked with a symbol, or other distinguishing marks, to identify the manufacturer or private label distributor, as appropriate. 15.3 Additionally, Type 3 weathering steel washers shall be identified with the symbol “3”. 15.7 It is possible that during the clipping of circular washers the marking symbols may be removed. This is acceptable provided that the majority of washers in the lot still display the identification marks. SOURCE: The informations above are from the ASTM F436 Standard that you can purchase on the ASTM Website.

F436-1 Chemical Properties

F436-3 Chemical Properties

Chemical Requirements^A For ASTM F436 Round & Bevel Washers Type 3^B
Element	Composition %
Element	Heat Anaysis	product Anaysis
Phosphorus Max	0.040	0.045
Sulfur Max	0.050	0.055
Silicon	0.15-0.35	0.13-0.37
Chromium	0.45-0.65	0.42-0.68
Nickel	0.25-0.45	0.22-0.48
Copper	0.25-0.45	**0.25-0.48

^A When providing Weathering Steels to a calculated corrosion index use the
Legault-Leckie formula calculator from Guide G101.

Legault-Leckie formula

^B Weathering steel washers may also be manufactured from any of the steels
listed in Table 2 of Specification A588/A588M and F3125.

Source: The table above is inspired by Table 1 from the ASTM F436 Standard that you can purchase on the ASTM Website

Permitted Coating

Information about Coating

4.2 Washers up to and including 11⁄2 in. for inch fasteners, shall be through hardened. Washers over 1 1⁄2 in. for inch fasteners may be either through hardened or carburized at the option of the manufacturer.
4.3 Zinc Coatings, Hot-Dip and Mechanically Deposited, Zinc/Aluminum Corrosion Protective Coating:
4.3.1 When zinc-coated washers are required, the purchaser shall specify the zinc coating process, for example, hot-dip, mechanically deposited, Zinc/Aluminum Corrosion Protective Coating, or no preference.
4.3.2 When hot-dip is specified the washers shall be zinc coated by the hot-dip process in accordance with the requirements of Specification F2329.
4.3.3 When mechanically deposited is specified the washers shall be zinc coated by the mechanical-deposition process in accordance with the requirements of Class 55 of Specification B695.
4.3.4 When Zinc/Aluminum Corrosion Protective Coating is specified, the washers shall be coated in accordance with the requirements of Grade 3 of Specification F1136
4.3.5 When no preference is specified, the supplier may furnish either a hot-dip zinc coating in accordance with Specification F2329, or a mechanically deposited zinc coating in accordance with Specification B695 , Class 55, or a Zinc/Aluminum Corrosion Protective Coating in accordance with Specification F1136, Grade 3. Threaded components (bolt and nuts) shall be coated by the same zinc-coating process and the supplier’s option is limited to one process per item with no mixed processes in a lot.
4.4 If washers are heat treated by a subcontractor, they shall be returned to the manufacturer for testing prior to shipment to the purchaser.

SOURCE: The informations above are from the ASTM F436 Standard that you can purchase on the ASTM Website.

Mechanical Properties

Information About Mechanical Properties

6.1 Through hardened washers shall have a hardness of 38 to 45 HRC, except when zinc-coated by the hot-dip process, in which case they shall have a hardness of 26 to 45 HRC.

6.2 Carburized washers shall be carburized to a minimum depth of 0.015 in. (inch series) and shall have a surface hardness of 69 to 73 HRA or 79 to 83 HR15N, except when zinc-coated by the hot-dip process, in which case they shall have a hardness of 63 to 73 HRA or 73 to 83 HR15N.

6.3 Carburized and hardened washers shall have a minimum core hardness of 30 HRC or 65 HRA.

SOURCE: The informations above are from the ASTM F436 Standard that you can purchase on the ASTM Website.

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ASTM F436

Hardened Steel Washers

Specifications

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