3/8 Fine Thread Bolt & 3/8 Inch Bolt 3/8 Shoulder Bolt | Factory
3/8 Fine Thread Bolt & 3/8 Inch Bolt & 3/8 Shoulder Bolt โ Precision Fasteners Direct from the Factory
๐ง Eliminate supply chain uncertainty. Get ISO 9001-certified 3/8โณ fasteners with full traceability, 30% lower cost than distributor pricing, and 15-day express delivery to US & European ports.
โ ๏ธ The Real Cost of Cheap 3/8โณ Fasteners
Procurement managers and technical directors face the same hidden risks โ hereโs what the data reveals.
Price vs. Total Cost
A 3/8 inch bolt bought at $0.08 may seem cheap, but failure rates of 3โ7% in field applications inflate TCO by 22โ40%. Distributor markups add 35โ55% on top of factory prices.
Downtime & Delays
A single 3/8 shoulder bolt strip can halt an assembly line for 2.5 hours. Our customers report 87% fewer rework events after switching to Boenโs precision-grade inventory.
Supply Chain Fragility
72% of US buyers experienced 3+ week delays with Asian suppliers in 2025. Inconsistent heat treatment and missing certifications cause costly customs holds at US & EU borders.
Unverified Quality
Without ISO 898-1 and RoHS reports, you risk liability. 3/8 fine thread bolt grades 8.8/10.9 must be verifiable โ we provide full mill test certificates with every batch.
โ Boen Fastener โ Engineered for Industrial Reliability
From material selection to final packaging, every 3/8 inch bolt, 3/8 shoulder bolt, and 3/8 fine thread bolt is made to exceed ASTM/ISO standards.
Factory-Direct Value
Eliminate 2โ3 middlemen. Our 3/8 fine thread bolt pricing is 30โ45% lower than equivalent distributor quotes. MOQ as low as 2,000 pcs for standard grades.
Precision Grade 8.8 / 10.9 / 12.9
All 3/8 shoulder bolt and 3/8 inch bolt products are cold-forged and heat-treated with Rockwell hardness testing per batch. Thread tolerance meets 6g/6h class.
Global Compliance Ready
Certified to ISO 9001, CE, RoHS, UL, and ASTM F568. Each 3/8 fine thread bolt order includes material traceability reports (MTR) and country-of-origin docs for smooth customs clearance.
15-Day Express to US/EU
Dedicated inventory of 3/8 inch bolt and 3/8 shoulder bolt stocked for rapid dispatch. Air + sea combined shipping โ CIF incoterms available. Real-time tracking via our portal.
OEM / Custom Shoulder Bolts
Need a custom 3/8 shoulder bolt with specific head height or undercut? Free design review within 48 hours. We support OEM drawing and ODM for construction, agriculture, and automotive.
ERP Integration & EDI
Direct integration with SAP, Oracle, and Microsoft Dynamics. Automated PO acknowledgments, ASN, and invoice matching. Reduce procurement admin time by 60%.
๐ Technical Specifications โ 3/8โณ Thread Fasteners
Full dimensional and mechanical data for 3/8 fine thread bolt, 3/8 inch bolt, and 3/8 shoulder bolt series.
| Parameter | 3/8 Fine Thread Bolt | 3/8 Inch Bolt (UNC) | 3/8 Shoulder Bolt |
|---|---|---|---|
| Thread | UNF 3/8โณ-24 | UNC 3/8โณ-16 | UNF 3/8โณ-24 / UNC 3/8โณ-16 |
| Grade | 8.8 / 10.9 / 12.9 | Grade 5 / Grade 8 | 10.9 / 12.9 |
| Material | Carbon Steel (C35 / 40Cr) | Carbon Steel / Alloy Steel | Alloy Steel (SCM435) |
| Finish | Zinc / HDG / Dacromet | Zinc / Black Oxide | Zinc / Phosphate / Teflon |
| Tensile (min) | 830 MPa (10.9) | 827 MPa (Grade 8) | 970 MPa (12.9) |
| Hardness | HRC 22โ32 | HRC 25โ34 | HRC 33โ39 |
| Certification | ISO 898-1 / RoHS | ASTM F568 / SAE J429 | ISO 898-1 / ASTM A574 |
| Packing | Bulk / Carton / Pallet | Bulk / Polybag / Pallet | Individually wrapped / Tray |
๐ Full MTR + third-party inspection report available per lot. Request sample test data with your inquiry.
๐๏ธ Where 3/8โณ Fasteners Perform Under Pressure
Agricultural Machinery
3/8 fine thread bolt used in tractor linkage arms โ zero field failure in 18-month trial.
Structural Steel
3/8 inch bolt (Grade 8) for beam connections โ 30% faster installation vs. welded joints.
Automotive Jigs
3/8 shoulder bolt as pivot pin โ 0.01 mm concentricity maintained over 100k cycles.
Heavy Equipment
3/8 fine thread bolt in hydraulic pump mounts โ resists 12.9 kN shear per bolt.
๐ค Trusted by Industrial Leaders Across 30+ Countries
Procurement Manager, Midwest Agri Equipment
โWe replaced our previous supplier with Boenโs 3/8 fine thread bolt. Cost per unit dropped 37% and field failure rate went from 4.2% to 0.3%. The MTRs are always accurate.โ
Supply Chain Director, Euro Build Systems
โBoenโs 3/8 inch bolt (Grade 8) performed flawlessly on our structural frames. Delivery 6 days early and all CE/ISO documents in order. We now use them for 80% of our fastener needs.โ
Engineering Manager, Auto Parts Inc.
โThe 3/8 shoulder bolt we ordered for our jig assembly had tolerance within ยฑ0.02 mm. Consistent hardness across 5,000 pieces. OEM support was excellent โ they modified head height per our drawing in 10 days.โ
๐ฌ Real Conversations with Our Clients
Senior Fastener Engineer & Export Quality Lead โ Handan Boen Fastener Mfg. Co., Ltd.
๐ง 12+ years in industrial fastener metallurgy and global supply chain. Michael oversees all 3/8 fine thread bolt, 3/8 inch bolt, and 3/8 shoulder bolt production lines, ensuring every batch meets ISO, ASTM, and customer-specific standards. He has personally audited 40+ factories and helped 200+ international buyers reduce fastener costs without compromising quality.
โ Frequently Asked Questions
๐ What is the difference between a 3/8 fine thread bolt and a 3/8 inch bolt (UNC)?
A 3/8 fine thread bolt uses UNF 3/8โณ-24 thread (24 threads per inch) and is ideal for applications requiring higher tensile strength and vibration resistance. A 3/8 inch bolt typically refers to UNC 3/8โณ-16 (16 TPI) and is better for general-purpose fastening with faster assembly. Boen supplies both in grades 8.8, 10.9, and 12.9.
๐ What is a 3/8 shoulder bolt used for?
A 3/8 shoulder bolt (also called a stripper bolt) has a precision-ground shoulder that acts as a bearing surface or pivot. It is commonly used in jigs, fixtures, dies, and machinery where accurate alignment and repeated motion are critical. Boen offers shoulder bolts with ยฑ0.01 mm shoulder tolerance.
๐ What certifications do your 3/8โณ bolts carry?
All our 3/8 fine thread bolt, 3/8 inch bolt, and 3/8 shoulder bolt products are certified to ISO 9001, CE, RoHS, and UL. Grade-specific certifications include ISO 898-1, ASTM F568, and SAE J429. We provide mill test certificates (MTR) and third-party inspection reports upon request.
๐ What is the minimum order quantity (MOQ) for 3/8โณ bolts?
For standard 3/8 inch bolt and 3/8 fine thread bolt in Grade 8.8 or 10.9, MOQ is 2,000 pieces per size. For 3/8 shoulder bolt and custom OEM parts, MOQ is 500 pieces. We also offer sample orders (50โ200 pcs) for qualification testing.
๐ How long does shipping take to the US or Europe?
We offer 15-day express delivery via air+sea combined for urgent orders. Standard sea freight is 25โ30 days to US West Coast and 30โ35 days to EU ports. We ship CIF, FOB, or DDP incoterms. Real-time tracking is provided for all shipments.
๐ Can you customize the head type or drive for a 3/8 shoulder bolt?
Yes. We offer OEM/ODM customization for 3/8 shoulder bolt including hex head, socket head, slotted head, and custom drive types (Torx, Phillips, etc.). Free design review within 48 hours โ just send your drawing or sample.
๐ Do you provide free samples for testing?
Absolutely. We offer free samples (up to 10 pieces) of our 3/8 fine thread bolt, 3/8 inch bolt, or 3/8 shoulder bolt for evaluation. You only pay for shipping. Request your sample kit today and test the quality firsthand.
๐ Ready to Cut Costs & Secure Your Supply Chain?
Get factory-direct pricing on 3/8 fine thread bolt, 3/8 inch bolt, and 3/8 shoulder bolt โ with full traceability and 15-day express delivery.
