Ultra-Twist
The ULTRA-TWIST Blind Fastening System
Fastener Dimensions (millimeters)
| Ultra Twist | A Body Diameter max |
min | B Width Across Flats basic |
max | min | C Width Across Corners max |
min | D Washer Outside Dia. max |
min |
| 20 | 20.8 | 20.4 | 32.0 | 32.0 | 30.8 | 37.0 | 36.2 | 37.9 | 37.5 |
| 24 | 24.7 | 24.3 | 41.0 | 41.0 | 40.2 | 47.3 | 46.5 | 47.6 | 47.0 |
| 27 | 28.7 | 28.3 | 46.0 | 46.0 | 45.1 | 53.1 | 52.3 | 50.9 | 50.3 |
| Ultra Twist | E Washer Thickness max |
min | F Drive Spline Dia. reference |
G Drive Spline Height reference |
H Nut Height max |
min | J Length reference |
||
| 20 | 13.5 | 13.2 | 13.5 | 18.0 | 19.8 | 19.5 | 48.0 | ||
| 24 | 13.8 | 13.4 | 15.0 | 18.0 | 21.8 | 21.4 | 55.0 | ||
| 27 | 14.2 | 13.7 | 18.0 | 18.0 | 25.9 | 25.5 | 60.0 | ||
Grip Data
| Grip Dash Number |
Grip Range (millimeters) |
20mm | L Length ± 1mm 24mm |
27mm | |||||
| -20 | 15.0 - 20.0 | 62.9 | 69.1 | N/A | |||||
| -25 | 20.0 - 25.0 | 67.9 | 74.1 | N/A | |||||
| -30 | 25.0 - 30.0 | 72.9 | 79.1 | 82.9 | |||||
| -35 | 30.0 - 35.0 | 77.9 | 84.1 | 87.9 | |||||
| -40 | 35.0 - 40.0 | 82.9 | 89.1 | 92.9 | |||||
| -45 | 40.0 - 45.0 | 87.9 | 94.1 | 97.9 | |||||
| -50 | 45.0 - 50.0 | 92.9 | 99.1 | 102.9 | |||||
| -55 | 50.0 - 55.0 | 97.9 | 104.1 | 107.9 | |||||
| -60 | 55.0 - 60.0 | 102.9 | 109.1 | 112.9 | |||||
| -65 | 60.0 - 65.0 | 107.9 | 114.1 | 117.9 | |||||
| -70 | 65.0 - 70.0 | 112.9 | 119.1 | 122.9 | |||||
| -75 | 70.0 - 75.0 | 117.9 | 124.1 | 127.9 | |||||
Material and Finish
| Core Pin | Nut | Bearing Washer | Shear Washer | Grip Sleeve | Bulb Sleeve | ||||
| Material | Alloy Steel | Alloy Steel | Alloy Steel | Alloy Steel | Alloy Steel | Carbon Steel | |||
| Finish | * | Electro-Zinc ASTM B633 |
* | None | None | None | |||
*Components are selectively lubed as needed for function, do not modify
Mechanical Properties
| Ultra-Twist Size |
Bolt Stress Area* mm² |
Minimum Clamp, kgf |
Tensile Strength min, kgf |
Shear Strength min, kgf |
|||||
| 20 | 169.0 | 13100 | 19200 | 20800 | |||||
| 24 | 235.0 | 17500 | 25700 | 29800 | |||||
| 27 | 321.0 | 24600 | 36200 | 40300 | |||||
*Based on 98% of thread pitch diameter
Installation Hole Sizes
| Ultra-Twist Size |
Recommended Drill Size (mm) |
Hole Diameter (mm)* Minimum |
Maximum | ||||||
| 20 | 21.5 | 20.9 | 21.6 | ||||||
| 24 | 26.0 | 24.8 | 26.1 | ||||||
| 27 | 30.0 | 28.8 | 30.1 | ||||||
*In drilling holes, care must be taken so that the back side is free of large burs
Installed Fastener Dimension
| Ultra-Twist | A ± .06 | B ± .03 | Z | K max | |||||
| 24 | .62 | 1.22 | .443 - .693 | 2.00 | |||||
| 28 | .79 | 1.44 | .497 - .747 | 2.35 | |||||
| 32 | .94 | 1.55 | .600 - .850 | 2.57 | |||||