Product Parameters
| Item | Specification |
|---|---|
| Material | Carbon Steel (10B21, 10B22), Alloy Steel (4340, 4140) |
| Grade | Grade 8, Grade 10, ASTM A490 |
| Thread | Metric (M6–M48), Imperial (1/4"–2") |
| Surface | Zinc Plated, Hot-Dip Galvanized, Plain |
| Application | Structural, machinery, pressure vessels |
| MOQ | 50 pcs |
description
High strength bolts are designed for one thing - carrying load without failing. The difference between a Grade 8 bolt and a Grade 10 bolt is not just a number; it is the difference between a connection that holds and one that does not, particularly in structural applications where bolt failure can mean catastrophic collapse. 10B21 and 10B22 are boron-treated carbon steels. Boron lets us use less carbon while still getting the hardenability needed for the head and thread areas - good machinability, good strength, reasonable cost. Grade 8 is the most common production grade for these materials. 4340 and 4140 alloy steels are where the higher grades live. ASTM A490 uses 4340 to deliver the combination of strength and toughness that critical structural connections demand.
Why Grade 8 for General Structural Work
Grade 8 bolts reach 150,000 psi tensile strength - enough for most structural connections without the cost premium of Grade 10. The 10B21 material machines cleanly and hardens predictably through the head and thread sections. If your connection requires more than Grade 8 can deliver, you are already in territory where the engineering calculation and installation controls matter more than the bolt grade itself.
FAQ
Q1: MOQ?
A1: 50 pieces.
Q2: Grades available?
A2: Grade 8 (10B21/10B22), Grade 10 (4340/4140), ASTM A490.
Q3: Materials?
A3: 10B21, 10B22 carbon steel. 4340, 4140 alloy steel for higher strength.
Q4: Surface finishes?
A4: Zinc plated, hot-dip galvanized, or plain - depends on the environment.
Q5: Thread standards?
A5: Metric M6 through M48. Imperial 1/4 inch through 2 inch.
Q6: Custom configurations?
A6: Yes. Custom lengths, thread specs, and material grades.
Quality is non-negotiable in precision manufacturing. Every component undergoes rigorous inspection at each stage of production.
- ISO 9001:2015 - Certified quality management system covering design, machining, and inspection
- Passivation / Electropolishing - ASTM A967 procedures for corrosion resistance
- Material Traceability - Heat number tracking from raw material to finished part
- First Article Inspection (FAI) - Full dimensional report included with every new order
From raw material to finished product, every step is controlled and documented:
- Material Preparation - CNC turning/milling to near-net shape
- Heat Treatment - Through-hardening or case-hardening for strength-critical parts
- Surface Preparation - Degreasing, acid cleaning, and surface activation
- Electroplating - Controlled bath process with thickness monitoring
- Sealing / Baking - Chrome sealing, anodize sealing, or hydrogen embrittlement relief baking
- Inspection - Coating thickness measurement, adhesion testing, and visual check
- Packaging - Protective interleaving, VCI packaging, and anti-tarnish wrapping
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