5/8-18 Bolt & 5 8 Bolt 5/8 Fine Thread Bolt 5/8 Shoulder Bolt | Factory
Eliminate supply chain risk with ISO 9001-certified 5/8 bolts, 5/8 fine thread bolts, and 5/8 shoulder bolts. Engineered for OEMs, distributors, and procurement teams who demand consistent quality, on-time delivery, and lower TCO.

๐ Handan, China โ 10+ years export expertise
Procurement and engineering leaders tell us the same frustrations โ here are the top 5 pain points we solve every day.
Inconsistent Thread Quality
A 5/8-18 bolt with poor thread fit causes assembly line stoppages. 15% of imported bolts fail first-pass inspection (industry benchmark).
Hidden Cost Overruns
Low-cost 5/8 bolts often arrive with 32% higher rejection rates, forcing emergency reorders and expedited freight.
Missed Delivery Windows
Container delays and poor inventory planning cost $2,800+ per hour in idle production time.
Compliance & Certification Gaps
Missing CE, RoHS, or ISO docs can block customs clearance. 1 in 5 shipments from unverified suppliers faces detention.
Limited Technical Support
No engineering guidance for custom 5/8 shoulder bolt or fine thread applications. Youโre left guessing.
๐ง OEM/ODM capability: custom head markings, special coatings, and packaging.
๐ Full documentation: mill certs, COA, COO, packing list, and commercial invoice.
| Parameter | 5/8-18 Bolt (UNC) | 5/8-24 Fine Thread Bolt | 5/8 Shoulder Bolt |
|---|---|---|---|
| Thread Pitch | 18 TPI | 24 TPI | 18 / 24 TPI (custom) |
| Diameter | 0.625" (15.875 mm) | 0.625" (15.875 mm) | 0.625" shoulder ร |
| Grade / Material | Grade 2, 5, 8 / 1018, 4140, 304SS | Grade 5, 8 / 4140, 316SS | 1018, 4140, 304SS, 316SS |
| Coating Options | Plain, Zinc, HDG, Dacromet | Zinc, Nickel, PTFE | Black oxide, Zinc, Passivated |
| Tensile Strength | Up to 150,000 psi (Grade 8) | Up to 150,000 psi (Grade 8) | 120,000โ150,000 psi |
| Certifications | ISO 9001, CE, RoHS, FCC | ISO 9001, CE, RoHS | ISO 9001, CE, RoHS, SGS |
*All dimensions in inches unless noted. Custom specs available for OEM programs.
5/8-18 bolts used in tractor hitches, harvester frames, and tillage equipment. 37% longer service life vs. standard imports.
5/8 fine thread bolts for steel beam connections, scaffolding, and heavy-duty anchoring. Zero field failures reported in 2024โ2025 audits.
5/8 shoulder bolts used in pivot joints, jig fixtures, and suspension components. ยฑ0.002" shoulder tolerance ensures repeatable assembly.

โWeโve been sourcing 5/8-18 bolts from Boen for 18 months. Price is 22% below our previous supplier, and quality is better. The team is responsive and logistics are smooth.โ

โThe 5/8 fine thread bolt samples passed our vibration test with flying colors. We placed a 50,000 pcs order immediately. Excellent communication and fast sampling.โ

โBoenโs 5/8 shoulder bolt is used in our robotic fixture arms. Zero defects in 12,000 pcs delivered. Shoulder tolerance is consistent at ยฑ0.002โ. Highly recommended.โ

Senior Technical Director at Handan Boen Fastener Manufacturing Co., Ltd. With 14 years of experience in fastener engineering and global supply chain, Zhang has overseen over 800+ B2B projects for clients across 30 countries. He specializes in bolt specification optimization, cost reduction through material science, and quality system implementation (ISO 9001, CE, RoHS).
โก Limited-time offer: Free samples + priority production slots for Q3 2026 orders placed before [date].
โ Risk-free: 100% money-back guarantee if first shipment fails inspection.
๐ง Email: shuan@fastenboen.com ยท mary@fastenboen.com ยท grace@fastenboen.com ยท stella@fastenboen.com
๐ Hanguang Industrial Park, Yongnian District, Handan City, Hebei Province, China ยท Daily 09:00โ17:00
๐ Trusted by Global Buyers โ Real Proof
๐ธ Automated cold heading line โ 5/8-18 bolt production
๐ฌ Dimensional inspection โ 5/8 fine thread bolt verification
Procurement Lead, Germany
โWe switched to Boen for our 5/8-18 bolt supply. Rejection rate dropped from 12% to 0.8%. Lead times are consistent โ 28 days door-to-door.โ
Supply Chain Manager, USA
โThe 5/8 shoulder bolt custom order was delivered ahead of schedule. Thread quality and shoulder tolerance are perfect for our jig fixtures.โ
Technical Director, UK
โBoenโs 5/8 fine thread bolt exceeded our fatigue test requirements. ISO 9001 and full traceability gave our compliance team confidence.โ