Patriot Bolt machines SAE J995 Grade 5 and Grade 8 nuts, the inch-series steel nuts matched to SAE J429 bolts, cap screws and studs. Grade 5 nuts are medium-carbon steel and Grade 8 nuts are medium-carbon alloy steel, both quenched and tempered.
We make J995 nuts alone or with matching J429 hex cap screws and bolts. Every order ships with mill test reports traceable to the heat.
SAE J995 Grade 5 / Grade 8 Nuts at a Glance
- Specification
- SAE J995 Grade 5 or Grade 8
- Grade 5
- Medium-carbon steel, quenched and tempered
- Grade 8
- Medium-carbon alloy steel, quenched and tempered
- Proof stress
- Grade 5: 120 ksi to 1 in · Grade 8: 150 ksi
- Matching bolts
- SAE J429 of the same grade
- Marking
- Grade 5: three marks or “5” · Grade 8: six marks or “8”
Why Match J995 Nuts to J429 Bolts
- Grade on grade. A Grade 8 bolt needs a Grade 8 nut. The nut grade must match or exceed the bolt grade.
- Bolt fails first. A matched set is designed so the bolt yields in tension before the nut threads strip.
- Common mistake. A Grade 5 nut on a Grade 8 bolt can strip at design load. Check the face markings before assembly.
SAE J995 Specifications
SAE J995 sets nut proof stress by grade and size.
| Grade | Proof stress, to 1 in | Proof stress, over 1 in | Material |
|---|---|---|---|
| 5 | 120 ksi | 105 ksi | Medium carbon, Q&T |
| 8 | 150 ksi | 150 ksi | Medium carbon alloy, Q&T |
Hardness limits are set by the specification for each grade and size. The certification for your order lists the results.
SAE J995 Nut Marking
| Grade | Typical marking |
|---|---|
| 5 | Three marks 120° apart, or the numeral 5 |
| 8 | Six marks 60° apart, or the numeral 8 |
Grade 2 nuts do not require a marking.
Nut Styles
- Hex nuts to ASME B18.2.2.
- Heavy hex nuts where a larger bearing face is needed.
- Threads: UNC or UNF, or the thread on your drawing.
Applications and Industries
- Machinery and equipment: Nuts for J429 cap screws and bolts. See Industrial Manufacturing.
- Oil and gas equipment: Skids, frames and rotating equipment mounts. See Oil & Gas.
- Vehicles and mobile equipment: Frame, suspension and attachment bolting.
Certification and Traceability
Patriot Bolt is ISO 9001:2015 certified. Each SAE Grade 5 / Grade 8 order includes mill test reports traceable to the heat, along with a certificate of conformance to the specification on your purchase order.
Nuts are marked with the grade symbol as the specification requires.
Compare SAE Grade 5 / Grade 8 with other bolting grades in our Fastener Materials Matrix.
SAE J995 Grade 5 / Grade 8 Nuts FAQ
Can I use a Grade 5 nut on a Grade 8 bolt?
No. The nut grade must match or exceed the bolt grade. A Grade 5 nut on a Grade 8 bolt can strip before the bolt reaches its rated load.
How do I tell Grade 5 and Grade 8 nuts apart?
Grade 5 nuts carry three marks or the numeral 5. Grade 8 nuts carry six marks or the numeral 8.
Do J995 nuts work with ASTM bolts?
J995 is written for SAE J429. For ASTM A449 and A354 bolts, the matching nut specification is ASTM A563.
Do you make matching J429 cap screws?
Yes. We machine SAE J429 Grade 5 and Grade 8 hex cap screws and bolts, so the bolt and nut can come from one source.
Request a Quote
Send us the alloy, nut style, thread size, specification and quantity, or upload your drawing. Our team will confirm the material and lead time. Call (281) 581-0176 or request a quote.
Related: SAE J429 fasteners hub · Hex head cap screws · A563 heavy hex nuts · All nuts