JIS B 1189 (Type 1):2014 Type 1 Hex Head Flange With Washer Bolt enhances bearing and mating performance through its flanged washer-style head. It is suitable for assemblies that require a clean appearance, stable clamping, and reduced management of loose washers.
The design improves production-line efficiency, reduces the risk of missing washers, and provides more uniform load distribution in thin plates, brackets, covers, and machinery accessories. The hex head remains compatible with common tightening tools.
Selection should consider flange diameter, bearing-surface form, thread size, and surface hardness. For batch supply, material, strength class, packaging, and rust prevention can be configured according to customer drawings or JIS-system requirements.

Dimensions unit: mm
| Thread size | M4 | M5 | M6 | M8 | M10 | M12 | ||
| d | ||||||||
| P | Coarse teeth | 0.7 | 0.8 | 1 | 1.25 | 1.5 | 1.75 | |
| Fine Teeth | / | / | / | 1 | 1.25 | 1.25 | ||
| ds | Max.=Nominal | 4 | 5 | 6 | 8 | 10 | 12 | |
| Min. | 3.9 | 4.9 | 5.9 | 7.85 | 9.85 | 11.8 | ||
| s | Max.=Nominal | 7 | 8 | 10 | 12 | 14 | 17 | |
| Min. | 6.8 | 7.8 | 9.8 | 11.75 | 13.75 | 16.75 | ||
| e | Min. | 7.74 | 8.87 | 11.05 | 13.25 | 15.51 | 18.9 | |
| dc | Max. | 10.5 | 12 | 14 | 17.5 | 21 | 25 | |
| dw | Min. | 7.5 | 9 | 11 | 14.5 | 18 | 22 | |
| k | Max. | 3.6 | 4.5 | 5.4 | 6.9 | 8.5 | 10.2 | |
| k1 | Min. | 2.4 | 3 | 3.6 | 4.8 | 6 | 7.2 | |
| c | Reference value | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 2 | |
| Max. | 0.95 | 1.15 | 1.4 | 1.6 | 1.85 | 2.25 | ||
| Min. | 0.65 | 0.85 | 1 | 1.2 | 1.35 | 1.75 | ||
| r1 | Max. | 0.6 | 0.7 | 0.8 | 1.1 | 1.4 | 1.6 | |
| r | Min. | 0.2 | 0.2 | 0.25 | 0.4 | 0.4 | 0.6 | |
| da | Max. | 4.7 | 5.7 | 6.8 | 9.2 | 11.2 | 14.2 | |
| kw | Min. | 1.6 | 2 | 2.3 | 3.1 | 3.9 | 4.7 | |
| x | 1.4 | 1.6 | 2 | 2.5 | 3 | 3.5 | ||
| Thread length b | - | - | - | - | - | - | ||
ABOUT US
Better Fastener is a professional fastener enterprise specializing in the manufacturing of steel washers, stainless steel washers, spring washers and sealingwashers. Founded in 2001 as a washer factory, the company expanded into a comprehensive enterprise integrating washers, nuts, bolts, spring nuts and other fastener products in 2010.
The company positions itself as a provider of comprehensive one-stop services for customers, relying on technological R&D, industrial investment and trade distribution.
With an experienced professional team and a sound sales network, Better Fastener has achieved excellent sales performance in both domestic and foreign markets,and has grown into one of the competitive manufacturers and suppliers in China's industrial fastener industry.
Better Fastener is committed to becoming a trusted fastener supplier for customers with reliable product quality, reasonable prices and on-time delivery
NEWS