SAE J429 Grade 5 Bolts
Grade 5 is medium-carbon steel, quenched and tempered. It is the most common inch grade on machinery, vehicles and equipment.
| Marking | 3 radial lines, 120 degrees apart, plus manufacturer ID |
|---|---|
| Matching nut | SAE J995 Grade 5 |
| Washer | SAE or USS flat; hardened where specified |
Mechanical properties (SAE J429)
| Size | Proof | Yield (min) | Tensile (min) | Hardness |
|---|---|---|---|---|
| 1/4 to 1 in | 85 ksi | 92 ksi | 120 ksi | C25 - C34 |
| over 1 to 1-1/2 in | 74 ksi | 81 ksi | 105 ksi | C19 - C30 |
Quick questions
| Can Grade 8 replace it? | Only when the designer or OEM allows it and the nut, washer and threads suit the higher load. |
|---|---|
| Can it replace A325? | No. A325 is a structural bolting system with its own head, thread length, nut, washer and installation rules. |
These tables carry the same figures as the printed sheet below.
The printed sheet
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Text version of this sheet
SAE J429 · inch steel bolts and screws · medium strength
FIELD IDENTIFICATION
What it is
Grade 5 is medium-carbon steel, quenched and tempered. It is the most common inch grade on
machinery, vehicles and equipment.
MFG
Marking
3 radial lines, 120 degrees apart, plus manufacturer ID
Matching nut
SAE J995 Grade 5
Washer
SAE or USS flat; hardened where specified
Grade 5: 3 radial lines, 120 degrees apart
Mechanical properties (SAE J429)
Size
Proof
Yield (min)
Tensile (min)
Hardness
1/4 to 1 in
85 ksi
92 ksi
120 ksi
C25 - C34
over 1 to 1-1/2 in
74 ksi
81 ksi
105 ksi
C19 - C30
Key points
Three lines identify Grade 5 in SAE J429. ASTM A449 Type 1 uses the same three-line mark, so read the maker and paperwork when it matters.
Class 8.8 metric is close in strength but a different standard, thread system and dimension series. Not interchangeable.
SAE J429 covers inch bolts and screws up to 1-1/2 in only. It is not a structural (F3125) or pressure/temperature (A193) specification.
Quick questions
Can Grade 8 replace it?
Only when the designer or OEM allows it and the nut, washer and threads suit the higher load.
Can it replace A325?
No. A325 is a structural bolting system with its own head, thread length, nut, washer and installation rules.
What it is not
Not a structural bolt (F3125 A325/A490).
Not an equivalent of 8.8 for replacement purposes.
Governing standards: SAE J429 (2014); SAE J995 (2017) (nuts). 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-FFEDE2 · thefastenerapp.com/fastener-guide/technical-reference/sae-j429-grade-5-bolts · © The Fastener App. Reference only — verify the current governing standard, drawing and manufacturer data before specifying or installing.
