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