ASTM F436 Hardened Washers
F436 washers are through-hardened steel washers made for high-strength and structural bolting. They spread load and give a hard surface under the turned element.
F436 at a glance
| Hardness | HRC 38 - 45 (lower range allowed for galvanized) |
|---|---|
| Sizes | 1/4 to 4 in |
| Shapes | Circular, clipped and beveled |
| Marking | F436 plus maker ID; Type 3 also marked 3 |
| Types | Type 1 plain/coated steel, Type 3 weathering |
These tables carry the same figures as the printed sheet below.
The printed sheet

See an error on this sheet?
Tell us what is wrong.
Text version of this sheet
ASTM F436 / F436M · hardened steel washers
What it is
FIELD IDENTIFICATION
F436 washers are through-hardened steel washers made for high-strength and structural bolting. They
spread load and give a hard surface under the turned element.
F436
Hardened round washer marked F436 + MFG
F436 at a glance
Hardness
HRC 38 - 45 (lower range allowed for galvanized)
Sizes
1/4 to 4 in
Shapes
Circular, clipped and beveled
Marking
F436 plus maker ID; Type 3 also marked 3
Types
Type 1 plain/coated steel, Type 3 weathering
Key points
A USS or SAE flat washer is not an F436. It will cup and lose preload under a structural bolt.
A490 bolts require F436 washers.
ASTM F844 washers are unhardened general-purpose washers; they are not a substitute for F436.
Governing standards: ASTM F436/F436M; ASTM F3125/F3125M-26; RCSC Specification. Editions shown are the latest confirmed as of September 2026. The drawing and the
governing standard always take precedence over this sheet.
torquing any fastener. Verify the current governing standard, project documents, OEM requirements, size, thread, coating and lot certification. To the fullest extent permitted by law, The Fastener App disclaims liability
arising from reliance on this reference.
Fastener Guide reference FG-6B8945 · thefastenerapp.com/fastener-guide/technical-reference/astm-f436-hardened-washers · © The Fastener App. Reference only — verify the current governing standard, drawing and manufacturer data before specifying or installing.

























