China hex flange bolts customized quotes

  • China hex flange bolts
  • China hex flange bolts
  • China hex flange bolts
Flange Head Bolt
  • 7-35 DAYS
  • 5000 TONS

Product name: Flange Bolts
Material: Carbon Steel, Alloy Steel, Stainless Steel
Standard: ASME/ANSI B 18.2.1, IFI111,DIN921, ISO4162, JIS B1189
Measurement system: INCH, Metric
Size: 1/4”-3”, M5-M64
Grade / Class: SAE J429 Gr.2, 5,8; ASTM A307Gr.A, Class 4.8, 5.8, 6.8, 8.8, 10.9, 12.9
Thread: M, UNC, UNF
Finish: Black Oxide, Zinc Plated(Clear/Blue/Yellow/Black), H.D.G. Y.Z.P. Plain, Nickel, Chrome
Customized: Available

Flange Bolts

Flange bolts are used on vehicle frames, especially truck frames, and anywhere a hex washer head bolt is needed. The large bearing surface distributes clamping force over a large area, allowing them to be used with irregular and oversized holes. Hex flange bolts are often used with Grade G Flange Style Lock Nuts to create a bolt/nut system that resists loosening and spans a wide area. They are also known as:  hex frame flange bolts, hex washer frame bolts, hex flange screws.  Serrated hex flange bolts have teeth under their head that grip the mating surface to resist loosening. 12 point flange bolts, also called  counterbore cap screws,  are used in aircraft and aftermarket automotive applications because they are easily installed using a 12 point socket and pneumatic impact wrench, while motorcycle enthusiasts like the small, externally wrenched decorative head.

Flange Bolt, Serrated HexThreads are standard right-hand. Hex and 12 point are available in Unified inch coarse series (UNC, Unified National Coarse) and Unified inch fine (UNF, Unified National Fine); serrated hex in Unified inch coarse. Flange bolts are partially and fully threaded depending on size and length. The point for hex types is chamfered or rounded; for 12 point, it's flat and chamfered.

Flange Bolt, 12 PointTypical sizes for hex range from 3/8" to 3/4"; #10 to 1/2" for serrated hex; and 1/4" to 1" in diameter for 12 point. Lengths for hex span from about 1" to 5"; 3/8" to 2 1/2" for serrated hex; and 1/2" to 7" for 12 point. Measure length from the underhead flange bearing surface to the threaded end of the bolt.

The flange bolt should be long enough to allow at least two full threads to extend beyond the nut face after tightening, which ensures full thread engagement with the nut. Conversely, there should be two full threads exposed on the head side of the nut to make sure the nut can be properly tightened. More exposed threads within the grip (the area between the head and nut) will result in a "springier" bolt. It is also recommended that threads not be in the shear plane(s).

The size of the head varies with the size of the flange bolt; the flange diameter of hex types is over 2.1 times the bolt size whereas 12 point heads are smaller at just 1.5 times. Tables 1 and 2 list head width across flats, which is wrench size, and across corners, flange diameter and head height.

Hex serrated, Grade 5, steel, zinc plated; hex, 150,000 PSI, steel, plain finish; and 12 point, alloy steel, plain finish, are common types. 150,000 is sometimes abbreviated 150M—"M" is the Roman numeral for 1,000. You may also see 150K—"K" refers to kilo, also an abbreviation for 1,000, which is based on a French modification of the Greek word chilioi. (Plain finish is unplated so there is no surface treatment to inhibit rust.)

When selecting a nut for use with a graded flange bolt, it is very important that the nut be the same grade as the bolt; one grade higher is also acceptable as one source states. Use hardened flat washers with bolt Grades 5 and 8. As for lock washers, which are often split (helical spring) type, use regular for Grade 2 and high strength alloy steel for Grades 5 and 8.

Always follow the manufacturer's recommendations regarding bolt reuse, thread lubricants/locking compounds and torque values.

Refer to Industrial Fasteners Institute Standards IFI-111, Hex Flange Screws, and IFI-115, Flange 12-Point Screws, for specifications relating to flange bolts.

Product Parameters

Product name: Flange Bolts

Material: Carbon Steel, Alloy Steel, Stainless Steel

Standard: ASME/ANSI B 18.2.1, IFI111,DIN921,  ISO4162, JIS B1189

Measurement system: INCH, Metric

Size: 1/4”-3”, M5-M64 

Grade / Class: SAE J429 Gr.2, 5,8; ASTM A307Gr.A, Class 4.8, 5.8, 6.8, 8.8, 10.9, 12.9

Thread: M, UNC, UNF

FinishBlack Oxide, Zinc Plated(Clear/Blue/Yellow/Black),  H.D.G.  Y.Z.P.  Plain, Nickel,  Chrome

Detailed Images

China hex flange bolts


Product name

Flange Bolts

Place of origin


Brand Name



Qingdao or according to requirement

Delivery time

Normally in 7-35 days, according to quantity


500kgs for each specification


According to customer’s requirement



 hex flange bolt consists of a hexagonal head and a flange (the gasket under the hexagon and the hexagon is fixed) and the screw (the cylinder with the external thread). The integral bolt is matched with the nut for fastening. A part that connects two through holes.

Flange bolt classification

1. hexagonal head type: one is flat brain, the other is concave brain.

2. surface color categories: according to different needs, the surface has white, military green, colored yellow, corrosion-resistant Dacromet.

3. Flange category: According to the different positions of the flange bolts, the size requirements of the discs are different, and the flat bottom and the thread are divided, and the thread have the anti-slip effect.

4. According to the way of connection, there are common and reamed holes. The flange bolts for the reaming holes should match the size of the holes and be used when subjected to lateral forces. In addition, in order to meet the need of locking after installation, there are holes in the rods, these holes can make the bolts not loose when they are vibrated. Some flange bolts are not threaded, so the thin rod flange bolts. This kind of flange bolt is beneficial to the coupling of the force.

We also accept customization order according to your samples and drawings

If you have other questions or concerns, please feel free to contact us.

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