HEX FLANGE SCREWS
Hex Flange Screws (also called Flange Bolts) incorporate a large bearing face (flange) into a one piece head design. The large bearing area under the head of this design provides additional benefits for assemblies over standard hex head cap screws:
Large bearing area under the head distributes clamp load over a larger area to resist fatigue loads. Minimizes indentation of the head into the material being bolted together to prevent loosening. Increases the heads resistance to rotation to prevent loosening in high vibration applications. Eliminates the need for a flat washer.
Hex Flange Screws are commonly called Frame Bolts because of their popularity in the trucking industry for use on assembly of truck frame rails. Hex Flange Screws are also used on pipe flange applications because the larger bearing area under the head helps ensure that the gasket is uniformly compressed to eliminate leaks. Hex Flange Screw can be used in any assembly that is currently using a hex cap screw and washer to eliminate the washer.
Earnest Machine Products line of Hex Flange Screws are made to the dimensions specified in the Industrial Fasteners Institute standard IFI -111. The head is manufactured with a full trimmed hex to prevent wrench slipping and rounding of the hex during installation or removal. The bearing faces are smooth to ensure uniform torque tension performance and that maximum clamp loads are achieved.
The material and physical properties meet the requirements specified in SAE J429 for Grade 8 screws.
Material: Alloy Steel per SAE J404
Tensile Strength: 150,000 psi min
Hardness: Rc 33/39
Inch
| Diameter |
Hex Size |
Flange
Dia |
Bearing
Dia |
Head
Thickness |
Flange
Thickness |
| F |
B |
B1 |
H |
K |
| Nom |
Max |
Min |
Max |
Min |
| 1/4 |
3/8 |
.56 |
.48 |
.28 |
.04 |
| 5/16 |
1/2 |
.68 |
.60 |
.32 |
.05 |
| 3/8 |
9/16 |
.81 |
.73 |
.39 |
.06 |
| 7/16 |
5/8 |
.93 |
.85 |
.46 |
.07 |
| 1/2 |
3/4 |
1.07 |
.98 |
.51 |
.08 |
| 9/16 |
13/16 |
1.19 |
1.10 |
.57 |
.09 |
| 5/8 |
15/16 |
1.33 |
1.23 |
.62 |
.10 |
| 3/4 |
1 1/8 |
1.59 |
1.47 |
.73 |
.11 |
Earnest Machine Products line of Metric Hex Flange Bolts are made to the dimensional tolerances specified by DIN 6921. The physical properties (material and tensile strength) meet the requirements of ISO 889-1 for Property Class 10.9
Metric
| Size |
Width Across Flats |
Across Corners |
Head Height |
Flange Dia. |
Flange Bearing Dia |
| A |
B |
C |
D |
E |
| Max |
Min |
Min |
Max |
Max |
Min |
| M6 |
10 |
9.78 |
10.95 |
6.6 |
14.2 |
12.2 |
| M8 |
13 |
12.73 |
14.26 |
8.1 |
18 |
15.8 |
| M10 |
15 |
14.73 |
16.5 |
9.2 |
22.3 |
19.6 |
| M12 |
16 |
15.73 |
17.62 |
11.5 |
26.6 |
23.8 |
| M16 |
21 |
20.67 |
23.15 |
14.4 |
35 |
31.9 |