Flange Bolts
Hex flange bolts have a hexagonal head with a built-in flange under the head. Unlike a standard hex bolt, the flange gives the bolt a larger bearing area, so the clamping load is spread over a wider surface when the bolt is tightened. This is useful when the fastener is installed directly against sheet metal, brackets, plates, or other parts where a larger bearing surface is preferred. The flange is formed as part of the bolt, so there is no separate washer to position during assembly in many applications.
We supply hex flange bolts in stainless steel, carbon steel, and alloy steel, with both metric and inch sizes available. Thread options, strength grades, flange designs, and surface finishes can be selected according to the required specification. For inch-series products, dimensions can be manufactured to ASME B18.2.1, while material and mechanical requirements can be matched to the applicable material or performance standard. Serrated flange bolts are also available where additional resistance to loosening is required.
Specification:
| Item | Metric Flange Bolts | Inch Flange Bolt |
|---|---|---|
| Size Range | M5-M20 | 1/4"-3/4" |
| Dimension Standard | DIN6921, JIS 1189 | ASME B18.2.1 |
| Thread | ISO Metric Coarse,Fine Thread | UNC,UNF |
| Thread Standard | ISO 261, ISO 965 | ASME B1.1 |
| Thread Tolerance | 6g | 2A |
| Material | Cabon Steel,Alloy Steel,Stainless Steel,Aluminum,Brass | Cabon Steel,Alloy Steel,Stainless Steel,Aluminum,Brass |
| Steel Property Class | ISO898-1,Class4.8,6.8,8.8,10.9,12.9 | SAE Grade2,5,8 |
| Stainless Steel Class | A2-70,A2-80,A4-70,A4-80 | F593C, F593D, F593G,F593H |
| Surface Treatment | Black Oxidation, Zinc Plated, HDG, Dacromet, Bright Finish,Passivation | |
| Inspection | Dimension,Thread,Mechanical Proeprty,Coating | |
Dimension Standard:
Hex flange bolts are manufactured to different dimensional standards depending on the market and application. We supply metric flange bolts according to DIN 6921 and JIS B 1189, as well as inch-series flange bolts according to ASME B18.2.1. Each standard defines the main dimensions of the bolt, including the head and flange geometry.
Below, you can find an overview of the dimensional standards we support. Click the standard or the corresponding image to view the detailed standard page, where you can find the complete dimension tables and specifications.
Mechanical Proeprty:
The mechanical requirements for our hex flange bolts depend on the material, grade, and applicable specification. For carbon steel and alloy steel bolts, we can supply metric products according to ISO 898-1 and inch-series products according to SAE J429. For stainless steel flange bolts, mechanical properties can be specified according to ISO 3506-1 for metric sizes or ASTM F593 for inch sizes. The common material is ss304&304L. and ss316&316L.
Available property classes and grades include options such as 8.8, 10.9, A2-70, A4-70, and other grades according to the selected material and standard. Tensile strength, yield or proof load, elongation, hardness, and other required properties are controlled according to the applicable specification. For special requirements, we can also manufacture and test flange bolts to customer drawings or specified material and performance requirements.
| Mechanical Proeprty Standard | ISO 898-1 | SAE J429 | ISO 3506-1 | ASTM F593 |
| Property Class | Class4.8,8.8,10.9,12.9 | GR.5,8,10 | A2-70,A2-80,A4-70,A4-80 | F593 C, F593 D,F593 G,F593 H |
Quality control of Flange Bolts:
We control the quality of our hex flange bolts from raw material inspection through final inspection. The main quality checks include:
| Inspect Item | Detail |
|---|---|
| Raw Material | We check the material grade and chemical composition against the specified requirements. Material certificates can be provided when required. |
| Dimensions | Critical dimensions such as bolt length, thread diameter, head width, head height, and flange diameter are checked against the applicable dimensional standard or customer drawing. |
| Thread Quality | Thread size, pitch, thread fit, and other thread requirements are checked with suitable gauges and measuring tools to ensure proper assembly. |
| Mechanical Properties | Tensile strength, yield or proof load, hardness, elongation, and other required properties are tested according to the specified material grade and performance standard. |
| Surface Finish | After surface treatment, we check the coating or finish for appearance, coverage, and other specified requirements. Available finishes include zinc plating, black oxide, zinc flake coatings, passivation, and other treatments according to the order. |
Related Bolt Products
In addition to hex flange bolts, we also supply other types of bolts for different assembly requirements. Depending on the joint design, installation method, available space, and required strength, customers can choose from standard heavy hex bolts, carriage bolts, hex bolts, stud bolts, U-bolts, anchor bolts, and T-bolts. Theese botls provide more options for machinery, steel structures, equipment, construction, and general industrial applications. Click on a product to view its specifications, applicable standards, materials, and available sizes.