Room 102, Building 13, Area A, Wanyang Zhongchuang Park, Ganyao Town, Jiashan County, Zhejiang China.
Both bolt types are essential in structural, automotive, and industrial applications, but their design differences dictate where and how they should be used. Misapplication often results in loosening, galling, or even catastrophic joint separation under load.
A standard fix bolt (often called a hex bolt) has a plain shank and relies entirely on a separate washer to distribute clamping force. In contrast, a flange bolt integrates a wide, forged collar beneath the head that acts as a built-in washer.
This integrated flange:
Flange bolts excel where material integrity is compromised—such as aluminum housings, composite panels, or painted surfaces prone to marring. Automotive exhaust manifolds, transmission mounts, and HVAC ducting commonly specify flange bolts to prevent crushing or leakage.
Standard fix bolts are preferred in high-tensile steel structures like bridges, machinery frames, and heavy equipment where maximum preload and fatigue resistance are critical. Their compatibility with hardened washers and locknuts also makes them ideal for dynamic-load environments.
Improper torque is the leading cause of bolt failure. Flange bolts typically require 10–15% less torque than equivalent standard bolts due to reduced friction under the head.
| Bolt Size | Standard Fix Bolt (ft-lb) | Flange Bolt (ft-lb) |
|---|---|---|
| 1/2"-13 | 105 | 90 |
| 9/16"-12 | 145 | 125 |
| 5/8"-11 | 195 | 170 |
Always verify torque values with manufacturer data, as coatings (e.g., zinc, PTFE), lubrication, and thread class significantly affect required preload.
Joint failures involving fix or flange bolts usually stem from one of three issues:
To mitigate these risks, use a calibrated torque wrench, apply consistent lubrication if specified, and never substitute bolt types without engineering review.

Fix anchorbolts include bolts, washers, nuts and 4PCS cylindrical shields. By tightening the bolts, the shields tubes expand and the components can be...
See Details
Flange bolts are specially used to tightly connect pipes and components with flanges. We produce flange bolts are solid t and durablethat, compling wi...
See Details
The Grade 8.8 black oxide full-thread hexagon socket bolts have an internal hex design and needs to be used with a wrench with a hex head. Its full th...
See Details
Grade 8.8 black oxide full-thread hexagon bolts is a very common fastener and requires a wrench or hex wrench to tighten it. Our hex head bolt meet th...
See Details
This product is made of high-quality carbon steel and undergoes a rigorous heat treatment process. It has high strength, good elasticity and toughness...
See Details
This 304 stainless steel plain full-thread hexagon bolt is a kind of fasteners made of high-quality stainless steel material and has corrosion resista...
See Details
This plain round flat head weld shoulder bolt is a fastener suitable for a variety of welding applications. Its flat head and round head design makes ...
See Details
This Grade 12.9 zinc plated countersunk head square neck plow bolt has the advantages of high precision, high operability, high strength, and high ten...
See Details