Large Flange Bolts & Long Flange Bolts Metric 12 Point Flange Bolts | Wholesale
Large Flange Bolts & Long Flange Bolts Metric 12 Point Flange Bolts | Wholesale
โ Large Flange Bolts & Long Flange Bolts โ Metric 12 Point Flange Bolts for Heavy-Duty Industrial Fastening
๐ง Engineered for high-clamp loads, vibration resistance, and rapid installation โ designed for automotive, agricultural, and construction OEMs who demand ISO-certified quality at factory-direct prices.
โญ Trusted by 300+ industrial buyers in 30+ countries | Lead time: 7โ25 days
โ ๏ธ The True Cost of Substandard Fasteners in Industrial Assembly
Unexpected Downtime
A single large flange bolt failure in a tractor PTO assembly can cause $12,000+ in unplanned repair costs and 3-day production halts.
Higher Scrap Rate
Using cheap long flange bolts with inconsistent thread pitch increases assembly rejection rates and field warranty claims by nearly a third.
Annual Liability Risk
A mid-size OEM faced $2.8M in recall costs due to metric 12 point flange bolts that loosened under vibration โ a failure that proper grade-10.9 fasteners could have prevented.
โ Bottom line: You don't just need a bolt โ you need a fully traceable, metallurgically certified flange bolt that eliminates these risks. That's exactly what we deliver.
๐งฉ Why Our Large Flange Bolts, Long Flange Bolts & Metric 12 Point Flange Bolts Outperform Commodity Fasteners
Factory-Direct Metallurgy
We source 100% domestic SAE 10B21 / 4137 / 40Cr alloy steel wire rod. Each heat lot is tested for tensile, yield, and hardness โ ISO 898-1 compliant. No third-party rerolling, no hidden chemistry shifts.
Precision 12-Point Spline Drive
Our metric 12 point flange bolts are cold-formed with ยฑ0.002" tolerance on the spline. This ensures 100% tool engagement, eliminates cam-out, and reduces installation torque variance by 34% vs. hex-head alternatives.
Extended Lengths for Deep Access
Our long flange bolts range from 30mm to 200mm+ in the same diameter series. The flange face is surface-ground to Ra โค 1.6 ยตm to distribute clamping force evenly across thin or soft substrates.
Vibration-Proof Serrated Flange
The serrated face on our large flange bolts provides โฅ 40% greater loosening resistance under ASTM A325 vibration testing compared to plain hex washer face designs. Ideal for engine mounts and chassis connections.
Full Traceability & Certification
Every batch ships with Material Certificate (EN 10204 3.1), dimensional inspection report, and factory test records. We are ISO 9001:2015 certified and fully compliant with EU Machinery Directive 2006/42/EC.
Wholesale Logistics Engine
We ship 10,000+ tons annually via our bonded logistics partners. FOB Tianjin / CIF Hamburg / DDP Chicago โ all incoterms available. Typical lead time 7โ25 days, with partial shipments allowed.
๐ Technical Specifications โ Large Flange Bolts, Long Flange Bolts & Metric 12 Point Flange Bolts
| Parameter | Large Flange Bolts | Long Flange Bolts | Metric 12 Point Flange Bolts |
|---|---|---|---|
| Diameter Range | M6 โ M30 (1/4" โ 1-1/8") | M8 โ M24 (5/16" โ 1") | M8 โ M20 (5/16" โ 3/4") |
| Length Range | 16mm โ 150mm | 30mm โ 200mm+ | 20mm โ 120mm |
| Grade / Property Class | 8.8 / 10.9 / 12.9 | 8.8 / 10.9 | 10.9 / 12.9 |
| Material | 40Cr, 4137, SAE 10B21 | 40Cr, SAE 10B21 | 4137, 40Cr, 4340 |
| Thread Standard | ISO 4032 / DIN 6923 | ISO 4032 / DIN 6923 | ISO 4032 / DIN 34800 |
| Flange Diameter | 1.5x โ 2.2x bolt dia. | 1.8x โ 2.5x bolt dia. | 1.6x โ 2.0x bolt dia. |
| Flange Face Surface | Serrated / Smooth | Serrated / Smooth | Serrated (standard) |
| Coating / Finish | Zinc, HDG, Dacromet, Geomet | Zinc, HDG, Dacromet | Zinc, Geomet, Black Oxide |
| Corrosion Resistance (NSS) | โฅ 480h (Geomet) | โฅ 480h (Geomet) | โฅ 720h (Geomet) |
| Certification | ISO 9001, CE, IATF 16949 (pending) | ISO 9001, CE | ISO 9001, CE, TรV (on request) |
๐ฌ *All dimensions in mm. Custom lengths, diameters, and coatings available for OEM/ODM orders. Contact us for a tailored specification sheet.
๐๏ธ Real-World Applications
Agricultural Machinery
Tractor PTO shafts, harvester frame joints, tillage equipment โ large flange bolts grade 10.9 with serrated face prevent loosening under high-vibration field conditions.
Automotive Drivetrain
Engine mounting brackets, transmission bell housing, suspension arms โ metric 12 point flange bolts provide the torque precision needed for automated assembly lines.
Steel Structure & Construction
Column base plates, beam splices, bracing connections โ long flange bolts offer the reach needed for built-up sections with thick gusset plates.
Industrial Gearboxes & Pumps
Flange-mounted motor interfaces, pump casings, hydraulic valve blocks โ the 12-point spline allows higher torque application without rounding, critical for high-pressure sealing.
โญ Real Reviews from Global Buyers
Procurement Manager, AgriParts GmbH (Germany)
"We switched to Boen for our large flange bolts grade 10.9. The fit consistency improved our assembly line uptime by 22%. The serrated flange really holds under vibration."
Supply Chain Director, Midwest Truck & Trailer (USA)
"Their long flange bolts saved us from a 6-week lead time elsewhere. We got 8,000 pcs M16x120mm in 18 days, complete with material certs. 37% cheaper than our previous supplier."
Technical Director, Hydraforce Pumps (UK)
"The metric 12 point flange bolts from Boen are the best we've tested. Spline engagement is nearly perfect, and the batch-to-batch hardness variation is less than 2 HRC. Highly recommended."
๐ฌ Real-Time Support โ What Our Customers Say
๐ธ Screenshots from real WhatsApp/Skype conversations with buyers in USA, Germany, and Australia.
โ Frequently Asked Questions
Q1: What is the minimum order quantity (MOQ) for large flange bolts?
For standard sizes (M8โM20), our MOQ is 5,000 pcs per item. For non-standard lengths or metric 12 point flange bolts, MOQ starts at 2,000 pcs. We can also accommodate trial orders of 500 pcs for qualified buyers.
Q2: Do you offer custom lengths for long flange bolts?
Yes. We offer custom lengths from 30mm up to 250mm in M8โM24 diameters. Provide your desired length, thread pitch, and flange OD, and we'll deliver a drawing within 48 hours. We also support OEM/ODM with your own branding on the head.
Q3: What coatings do you recommend for corrosion resistance on metric 12 point flange bolts?
For outdoor or marine environments, we recommend Geometยฎ (Zn-Al flake coating) which provides โฅ720h NSS corrosion resistance. For automotive underhood applications, Dacrometยฎ is preferred. Standard zinc plating (Fe/Zn 8โ12 ยตm) is available for indoor use.
Q4: How do you ensure the quality of large flange bolts before shipment?
Every batch undergoes 3-stage inspection: (1) in-process dimensional check using vision systems, (2) mechanical testing (tensile, yield, hardness, wedge load) per ISO 898-1, and (3) final random sampling per AQL 2.5. We provide a full inspection report with each shipment.
Q5: What is the typical lead time for wholesale orders of long flange bolts?
Standard sizes: 7โ15 days from order confirmation. Custom lengths or coatings: 15โ25 days. We offer urgent partial shipment at no extra cost. We ship via FOB, CIF, or DDP โ all major ports worldwide.
Q6: Can you provide metric 12 point flange bolts with a retained washer or serrated flange?
Absolutely. Our standard 12-point flange bolts come with a serrated flange face as default. We also offer a retained washer version (captive washer) for applications where additional bearing surface is needed. Both are available in grade 10.9 and 12.9.
Q7: Do you have stock in the USA or Europe for large flange bolts?
We maintain buffer stock in Hamburg (Germany) and Chicago (USA) for fast-moving sizes (M10โM20, grade 8.8/10.9). Typical delivery from these hubs: 2โ5 days. Contact us for real-time stock availability in your region.
Q8: How do I request a quote or sample for metric 12 point flange bolts?
Simply fill out the form below, email us at shuan@fastenboen.com, or reach us on WhatsApp. We'll respond within 4 hours with a quotation, stock availability, and a free sample request link. First sample is free โ you only pay shipping.
Michael has 14 years of experience in industrial fastener design and metallurgy at Handan Boen Fastener Manufacturing Co., Ltd. He has personally overseen the production of over 50,000 tons of flange bolts for global OEMs and holds a degree in Mechanical Engineering from Hebei University of Technology. His technical insights are grounded in day-to-day factory floor reality.
๐ Ready to Secure Your Supply Chain with Certified Flange Bolts?
โ Free samples available | โ 15-day lead time on standard sizes | โ Factory-direct pricing โ save 20โ37% vs. distributors
๐ง shuan@fastenboen.com | mary@fastenboen.com | grace@fastenboen.com | stella@fastenboen.com
๐ Hanguang Industrial Park, Yongnian District, Handan, Hebei, China | MonโSat 09:00โ17:00
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๐ญ Trusted by Global OEMs โ See Our Factory & Certifications
โ๏ธ Automated Cold Heading โ 600 pcs/min
๐ฅ Continuous Mesh Belt Furnace โ ISO 898-1
๐ CMM & Hardness Lab โ 100% Traceability
โ Trusted by leading industrial brands worldwide: