Extracting Rounded Bolt Heads and Nuts

Rounded Bolt
Rounded Bolt

Weld a Nut to the Stripped Bolt

Placing a larger nut on top of the stripped bolt and welding the center of the nut to the top of the bolt will often allow the bolt to be safely removed.

Cut a Slot in the Bolt and Use an Impact Driver

Cut a slot in the bolt head with a hack saw, cut off tool or Dremel. Once you have the slot cut use a straight blade in a impact driver to help remove the bolt. Be careful not to use this on aluminum or any other materials that are easily damaged.

Where to Buy Impact Drivers

  • Craftsman Impact Driver

Apply Heat

If you have a propane torch you can apply heat to the bolt to help loosen it. Be careful using an open flame around an engine bay or any other location where there could be flammable material.

Weld a Wrench to the Stripped Bolt

Spray with Penetrating Oil

Soaking for 5 minutes should work in most cases. If the bolt remains stuck, soaking for an additional 24 hours may help.

Remove Stripped Nut or Bolt with Vise Grips

With vise grips you may be able to get a good enough grip on what's left of the bolt to remove it. Locking wrench vise grips are best suited to give you maximum grip on a hex bolt. The second best vise grip for removing a nut or bolt are straight jaw vise grips.

Locking Wrench and Straight Jaw Locking Pliers (Vise-Grip) Comparison

Locking Wrench Price Average Customer Rating Reviews Minimum Jaw Capacity Maximum Jaw Capacity Length
IRWIN Tools VISE-GRIP Locking Wrench #4LW $11.99 4.6 251 0.25 in 0.5625 in 4 in
IRWIN VISE-GRIP Locking Wrench #10LW $15.07 4.8 169 0.625 in 1.125 in 10 in
IRWIN VISE-GRIP Locking Wrench #7LW $11.85 4.73 24.0 0.4375 in 0.75 in 7 in
Milwaukee 10 in. Torque Lock Straight Jaw Locking Pliers #48-22-3510 $12.97 4.6 132 1.75 in 10 in

File Down or Grind Opposing Edges of the Bolt and Try Vice Grips

You can file down opposing edges of a bolt or nut so that there are 2 flat edges and then try vice grips again. This may be enough to give the vice grips enough of a bite.

Remove a Stripped Bolt With a Bolt Out Set

Use a bolt out set, these tend to work best if you have enough room to hammer them onto the stripped bolt.

Nut and Bolt Extractor Comparison

Nut/Bolt Extractor Price Reviews Average Review Drive US Sizes Metric Sizes Warranty
Craftsman 10 pc. Damaged Bolt/Nut Remover Set, Low Profile Bolt-Out #52166 $31.99 195 4.42 3/8 in ratchet 3/8 in, 7/16 in, 1/2 in, 5/8 in, 3/4 in 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17mm, 19 mm No
Craftsman Bolt-Out 5 pc. Damaged Bolt/Nut Remover Set Model #52061 $39.99 382.0 3.02 1/2 in ratchet 9/16 in, 5/8 in, 11/16 in, 3/4 in 14 mm, 15 mm, 16 mm, 17 mm, 19 mm No
IRWIN HANSON BOLT-GRIP Bolt Extractor Base Set, 5 Piece, #394001 $19.98 1502 4.49 3/8 in ratchet 3/8", 7/16", 1/2", 9/16", 5/8" 11 mm, 14 mm, 16 mm
Pittsburgh 9 Pc 3/8 in. Drive Metric Bolt Extractor Socket Set #67894 $2999.0 0 3/8 in ratchet 8 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 16 mm, 17 mm, 19 mm
9 Pc 3/8 in. Drive SAE Bolt Extractor Socket Set #67897 2.99 0 3/8 in ratchet 1/4 in, 5/16 in, 3/8 in, 7/16 in, 1/2 in, 9/16 in, 5/8 in, 11/16 in, 3/4 in

Cut Groove Into the Bolt Head and Use a Straight Blade Screwdriver

Use a hack saw, air cut off tool or a Dremel to cut a grove into the bolt head and then use a straight blade screw driver to remove it.

Remove a Bolt With a Snapped Off Head

Drill Out Set

A drill out set should only be used when the head of the bolt has been snapped off and the rest of bolt is recessed in a hole. Be sure to run the drill in reverse when drilling the hole as the bits in drill out sets are meant to run in reverse. Also, make sure to run the drill out very slowly as they are prone to breaking. Make sure to drill the hole in the direct center of the bolt. A center punch can help to make sure you have the exact center of the bolt.

Drill Out Sets

  • Craftsman 4 pc. Drill-Out Power Extractor
  • QuikCenter

Use a Threaded Insert

Drill the bolt out with the proper size drill bit that will fit the Heli-Coil that you need to put in.