SAE J429 Grade 5 Bolts
SAE J429 Grade 5 — the medium-strength quenched-and-tempered inch-series workhorse: 120 ksi minimum tensile, 85 ksi proof load and C25–C34 hardness from 1/4″ through 1″, stepping down to 105/74 ksi over 1″ through 1-1/2″. Three radial head lines, 120° apart.
Last updated: 2026-11
Specifications
Grade 5 is the default answer in North American industrial practice when "high-strength bolt" is said without a standard: medium-carbon steel quenched and tempered, marked with three radial lines so the grade can be counted at a glance, and strong enough for automotive, OEM equipment and machinery drawings that default to SAE grades. Its mechanical table carries the same size-dependence that Grade 2 shows, in milder form — full 120 ksi tensile and 85 ksi proof only through 1″, with the over-1″ band specified at 105/74 ksi — so the diameter on the RFQ is part of the strength statement, not just a dimension. Where a drawing uses ASTM language, Grade 5 is the functional counterpart of A449 with similar strength up to 1″; the matched nut is SAE J995 Grade 5 (or ASTM A563 A/DH) with F436 hardened washers wherever the joint is tensioned.
| Standard | SAE J429 Grade 5 — mechanical and material requirements for externally threaded inch-series fasteners |
|---|---|
| Head marking | 3 radial lines at 120° spacing, plus the manufacturer symbol |
| Material | Medium carbon steel (0.28–0.55% C), quenched and tempered; boron additions permitted |
| Min. tensile | 120 ksi (1/4″ through 1″); 105 ksi (over 1″ through 1-1/2″) |
| Min. yield | 92 ksi (1/4″ through 1″); 81 ksi (over 1″ through 1-1/2″) |
| Min. proof load | 85 ksi (1/4″ through 1″); 74 ksi (over 1″ through 1-1/2″) |
| Hardness | Rockwell C25–C34 (HRC) through 1″; C19–C30 over 1″ through 1-1/2″ |
| Size range | 1/4″ through 1-1/2″ — the mechanical step at 1″ is part of the grade |
| Typical pairing | SAE J995 Grade 5 or ASTM A563 Grade A/DH nut; F844 washer, F436 hardened where tensioned |
| ASTM counterpart | Functionally equivalent to ASTM A449 (medium-strength Q&T, similar strength up to 1″) |
Materials
- Medium carbon steel (0.28–0.55% C), quenched and tempered
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (SAE J429 Grade 5 Bolts) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 1,000–10,000 pieces depending on size. Stock items run 3–7 days. High-strength and custom parts run 15–25 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
Grade 5 or ISO Class 8.8 — are they interchangeable?
Not on a drawing that names either one. Class 8.8 specifies 800 MPa minimum tensile (≈116,000 psi) — the common "8.8 ≈ Grade 5" shorthand is close on tensile but approximate: the proof-load definitions and test methods differ between ISO 898-1 and SAE J429, and the size bands are not aligned (Grade 5 steps at 1″ and 3/4″ in inch series; 8.8 steps at M16). The collected specification makes the working rule explicit: SAE and ASTM equivalents are acceptable substitutions when no specific SAE callout is mandated — so read the drawing first, and when you send the RFQ, name the standard the drawing carries.
When does Grade 5 need the F436 washer instead of a plain F844?
When the joint is actually tensioned. The collected pairing table puts F844 plain under Grade 2 as a general-purpose washer and keeps it for Grade 5 at rest, but specifies F436 hardened wherever the Grade 5 connection is tensioned — a soft washer under a preloaded bolt loses thickness under the nut rotation and takes preload out of the joint. The nut side matters the same way: J995 Grade 5 or A563 A as a floor, DH where the joint is tensioned, so the assembly fails in the bolt shank rather than by nut thread stripping.
What is the MOQ and lead time for this bolt grade?
The minimum order quantity is 1,000–10,000 pieces depending on size. Stock items ship in 3–7 days; high-strength and custom parts in 15–25 days. Common diameters in this grade are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
What should an RFQ for this bolt grade state?
State the standard and grade (for example ISO 4017 Class 8.8 or ASTM F3125 Grade A325 Type 1), diameter and length, thread type (metric coarse or UNC/UNF), finish (plain, zinc, or hot-dip galvanized where the grade permits), required certificates such as a mill test report per EN 10204 3.1, and quantity per size — plus destination country.
Related knowledge
- What Bolt Property Classes 8.8, 10.9 and 12.9 Encode — and When High Strength Stops Being the Right Choice
- Bolt Grade Selection: ISO 898-1 8.8/10.9/12.9 vs ASTM A307 and A325
- 8.8 vs 10.9 vs 12.9 Bolts: Strength, Hardness and Cost — What the Evidence Settles
- Calculating Bolt Preload and Clamp Force: Torque, Friction and Tightening Method
- How to Determine Tightening Torque and Choose a Tightening Method for a Bolted Joint
- Fastener Failure Modes: Which Fatigue, Creep and SCC Controls the Evidence Supports
- Hydrogen Embrittlement in High-Strength Bolts: Which Grades Need Controls, Which Coatings and Baking Schedules Are Acceptable, and What to Require Before the RFQ
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support