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JIS B 1189:2014 Coarse Thread Grade A Hex Flange Bolt
JIS B 1189:2014 Coarse Thread Grade A Hex Flange Bolt is used in Japanese-standard fastening systems that require dimensional consistency, quick engagement, and a stable bearing surface. The Grade A designation makes it suitable for standardized production and refined assembly.
The coarse thread supports faster installation and better tolerance of minor contamination, while the flange distributes clamp pressure and reduces dependence on separate washers. Typical uses include vehicle parts, machinery brackets, equipment mounting plates, and production lines.
The product can be customized by strength class, material, and surface treatment. For projects requiring both quick installation and controlled joint quality, tightening specifications and matching nut or tapped-hole accuracy should be confirmed at the same time.
Dimensions unit: mm
| Thread size | M5 | M6 | M8 | M10 | M12 | (M14) | M16 | ||||
| d | |||||||||||
| P | Pitch | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2 | |||
| b | Reference | L≤125 | 16 | 18 | 22 | 26 | 30 | 34 | 38 | ||
| 125＜L≤200 | / | / | 28 | 32 | 36 | 40 | 44 | ||||
| L＞200 | / | / | / | / | / | / | 57 | ||||
| c | Min. | 1 | 1.1 | 1.2 | 1.5 | 1.8 | 2.1 | 2.4 | |||
| da | Type F | Max. | 5.7 | 6.8 | 9.2 | 11.2 | 13.7 | 15.7 | 17.7 | ||
| Type U | Max. | 6.2 | 7.5 | 10 | 12.5 | 15.2 | 17.7 | 20.5 | |||
| dc | Max. | 11.4 | 13.6 | 17 | 20.8 | 24.7 | 28.6 | 32.8 | |||
| ds | Max. | 5 | 6 | 8 | 10 | 12 | 14 | 16 | |||
| Min. | 4.82 | 5.82 | 7.78 | 9.78 | 11.73 | 13.73 | 15.73 | ||||
| du | Max. | 5.5 | 6.6 | 8.8 | 10.8 | 12.8 | 14.8 | 17.2 | |||
| dw | Min. | 9.4 | 11.6 | 14.9 | 18.7 | 22.5 | 26.4 | 30.6 | |||
| e | Min. | 7.59 | 8.71 | 10.95 | 14.26 | 16.5 | 19.86 | 23.15 | |||
| k | Max. | 5.6 | 6.9 | 8.5 | 9.7 | 12.1 | 12.9 | 15.2 | |||
| k1 | Min. | 2.3 | 2.9 | 3.8 | 4.3 | 5.4 | 5.6 | 6.8 | |||
| f | Max. | 1.4 | 1.6 | 2.1 | 2.1 | 2.1 | 2.1 | 3.2 | |||
| r1 | Min. | 0.2 | 0.25 | 0.4 | 0.4 | 0.6 | 0.6 | 0.6 | |||
| r2 | Max. | 0.3 | 0.4 | 0.5 | 0.6 | 0.7 | 0.9 | 1 | |||
| r3 | Max. | 0.25 | 0.26 | 0.36 | 0.45 | 0.54 | 0.63 | 0.72 | |||
| Min. | 0.1 | 0.11 | 0.16 | 0.2 | 0.24 | 0.28 | 0.32 | ||||
| r4 | Reference value | 4 | 4.4 | 5.7 | 5.7 | 5.7 | 5.7 | 8.8 | |||
| s | Max. | 7 | 8 | 10 | 13 | 15 | 18 | 21 | |||
| Min. | 6.78 | 7.78 | 9.78 | 12.73 | 14.73 | 17.73 | 20.67 | ||||
| V | Max. | 0.15 | 0.2 | 0.25 | 0.3 | 0.35 | 0.45 | 0.5 | |||
| Min. | 0.05 | 0.05 | 0.1 | 0.15 | 0.15 | 0.2 | 0.25 | ||||
| Thousand pieces of steel weigh ≈kg | - | - | - | - | - | - | - | ||||
| Thread length b | - | - | - | - | - | - | - | ||||
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