Ko-Ken KO4129-37-08 Bolttwister Broken Bolt Remover, 8 mm
Out of stock
Ko-Ken 4129-37 and 4129-75 are Bolttwister broken bolt removers.
Sizes run from 8 to 16 mm.
Lengths are 37 and 75 mm. (manufacturer-stated)
Each model is listed in the table below with its specifications.
Where this product is used
- Removing a twisted off bolt whose head has come off
- Broken studs and bolts after a pilot hole has been drilled
- Workshop and on-site repair work
Features
- Sharp spiral edges hold the broken bolt (manufacturer-stated)
- Selection table printed in the catalogue gives the bolt size and pilot hole drill size for each Bolttwister size (manufacturer-stated)
Key specifications
| Model | Size | Length | Bolt size | Drill size | Weight |
|---|---|---|---|---|---|
| KO4129-37-08 | 8 mm | 37 mm (manufacturer-stated) | M14 to M16 (manufacturer-stated) | 8.2 to 8.5 mm (manufacturer-stated) | 59 g (manufacturer-stated) |
| KO4129-37-10 | 10 mm | 37 mm (manufacturer-stated) | M18 to M20 (manufacturer-stated) | 10.2 to 10.5 mm (manufacturer-stated) | 63 g (manufacturer-stated) |
| KO4129-37-12 | 12 mm | 37 mm (manufacturer-stated) | M22 to M24 (manufacturer-stated) | 12.2 to 12.5 mm (manufacturer-stated) | 67 g (manufacturer-stated) |
| KO4129-37-14 | 14 mm | 37 mm (manufacturer-stated) | M27 to M30 (manufacturer-stated) | 14.2 to 14.5 mm (manufacturer-stated) | 72 g (manufacturer-stated) |
| KO4129-37-16 | 16 mm | 37 mm (manufacturer-stated) | M33 (manufacturer-stated) | 16.2 to 16.5 mm (manufacturer-stated) | 78 g (manufacturer-stated) |
| KO4129-75-08 | 8 mm | 75 mm (manufacturer-stated) | M14 to M16 (manufacturer-stated) | 8.2 to 8.5 mm (manufacturer-stated) | 80 g (manufacturer-stated) |
| KO4129-75-10 | 10 mm | 75 mm (manufacturer-stated) | M18 to M20 (manufacturer-stated) | 10.2 to 10.5 mm (manufacturer-stated) | 94 g (manufacturer-stated) |
| KO4129-75-12 | 12 mm | 75 mm (manufacturer-stated) | M22 to M24 (manufacturer-stated) | 12.2 to 12.5 mm (manufacturer-stated) | 110 g (manufacturer-stated) |
| KO4129-75-14 | 14 mm | 75 mm (manufacturer-stated) | M27 to M30 (manufacturer-stated) | 14.2 to 14.5 mm (manufacturer-stated) | 130 g (manufacturer-stated) |
| KO4129-75-16 | 16 mm | 75 mm (manufacturer-stated) | M33 (manufacturer-stated) | 16.2 to 16.5 mm (manufacturer-stated) | 150 g (manufacturer-stated) |
Lengths, bolt sizes, drill sizes and weights are manufacturer-stated (Ko-ken catalogue 2025-26).
Selecting the right option
Choose the Bolttwister size from the selection table: the bolt size and the pilot hole drill size for each size are listed with the specifications. To use it, drill a hole in the centre of the broken bolt, drive the Bolttwister firmly into the hole and turn it counterclockwise until it grips; the sharp spiral edges hold the broken bolt so it can be removed by continuing to turn. (manufacturer-stated)
Related products
Related Ko-Ken products: Ko-Ken 3129-32 Bolttwister Broken Bolt Remover, 2 mm, 3/8 in Drive and Ko-Ken 4405A 12-Point Socket, Inch Sizes, 1/2 in Drive.
Couldn't load pickup availability
Secure Checkout. We do not store credit card details
-
8mm / 37mm socket
Model Number: KO4129-37-08
-
8mm / 75mm socket
Model Number: KO4129-75-08
-
10mm / 37mm socket
Model Number: KO4129-37-10
-
10mm / 75mm socket
Model Number: KO4129-75-10
-
12mm / 37mm socket
Model Number: KO4129-37-12
-
12mm / 75mm socket
Model Number: KO4129-75-12
-
14mm / 37mm socket
Model Number: KO4129-37-14
-
14mm / 75mm socket
Model Number: KO4129-75-14
-
16mm / 37mm socket
Model Number: KO4129-37-16
-
16mm / 75mm socket
Model Number: KO4129-75-16
