ASTM F436 Hardened Steel Washers
The hardened washer for structural and high-strength bolting: through hardened to 38 to 45 HRC, flat, clipped or beveled, plain or galvanized — required under the turned element of A325 and A490 assemblies.
What F436 washers is.
ASTM F436 covers the hardened washers used with high-strength bolts. Through-hardened washers are 38 to 45 HRC, or 26 to 45 HRC when hot-dip galvanized, and carburized washers may be used in the smaller sizes with a surface hardness of 69 to 73 HRA. Styles include circular, clipped circular, extra-thick and beveled for use on sloping flanges, in Type 1 carbon steel and Type 3 weathering steel. Dimensions are given in the specification for inch and metric sizes.
We machine F436 washers in the odd sizes, thicknesses and clipped shapes that stock does not cover, have them heat treated to the specification, and supply them plain or galvanized with matching bolts and nuts.
Chemical composition.
| Element | Type 1 | Type 3 | — |
|---|---|---|---|
| Phosphorus, max | 0.040 | 0.040 | |
| Sulfur, max | 0.050 | 0.050 | |
| Silicon | — | 0.15–0.35 | |
| Chromium | — | 0.45–0.65 | |
| Nickel | — | 0.25–0.45 | |
| Copper | — | 0.25–0.45 |
Values per ASTM F436/F436M-19 Table 1 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
Mechanical properties.
| Washer type and finish | Hardness | — | — | — | — |
|---|---|---|---|---|---|
| Through hardened, plain or mechanically galvanized | 38–45 HRC | ||||
| Through hardened, hot-dip galvanized | 26–45 HRC | ||||
| Carburized (sizes permitted), surface | 69–73 HRA | ||||
| Carburized, core | 30 HRC / 65 HRA min |
Values per ASTM F436/F436M-19 clause 6.1 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
Specifications that apply.
How F436 washers ships from Houston.
- Hex and heavy hex bolts and cap screws
- Studs and threaded rod
- Nuts and washers to match
- Machined specials to drawing
F436 washers fasteners we make.
Every item is manufactured to your drawing or standard in F436 washers, imperial or metric, with an EN 10204 3.1 certificate.
Why a hardened washer
When a high-strength bolt is tightened, the nut or head turns against the joint under a bearing stress that would gall or dish a soft washer and lose bolt tension. A washer at 38 to 45 HRC spreads the load, gives the nut a consistent surface to turn on, and protects a galvanized or painted joint. Structural specifications require one under whichever element is turned, and beveled washers restore a flat seat on channel and beam flanges that slope.
Testing, certification and marking
- Hardness tested per lot
- Manufacturer's identification and type mark (3 for weathering steel) where size allows
- Certificate of conformance with heat number
- Galvanizing thickness reported when coated
ASTM F3125 Grade A325 Structural Bolts (120 ksi)
The structural steel connection bolt: heavy hex head, 120 ksi tensile, ½ to 1½ in., quenched and tempered, with the twist-off F1852 and metric A325M variants in the same specification.
ASTM F3125/F3125M Grade A490 · Type 1 and Type 3ASTM F3125 Grade A490 Structural Bolts (150 ksi)
The high-strength structural bolt: alloy steel, 150 to 173 ksi tensile, ½ to 1½ in., never hot-dip galvanized — with the twist-off F2280 and metric A490M variants in the same specification.
ASTM A563 / A563MASTM A563 Carbon and Alloy Steel Nuts (Grades A, B, C, D, DH, DH3)
The nut specification for carbon and alloy steel bolting: Grade A for A307, Grade B for cast-iron flanges, C and D for 105 to 120 ksi bolts, and DH and DH3 heat treated for A325, A490, A354 and Grade 8 — with proof stress by grade and style.