Mayhew Tools 37315 Pneumatic Bolt Breaker, 3/8", Black Oxide Finish

A must for automotive under body work in the rust belt. I used it to get out some M6’s that would have snapped off with any other means. No damage what so ever to anything, the socket, fasteners, and surrounding areas were completely undamaged. Zero reservations about reusing the bolts. This product is at least as good as percussion and nearly as good as heat (propane torch). FAR BETTER than ANY penetrating oil. The bolt cracking loose is the oddest feeling. Id highly recommend an air chisel with a regulator. My 114GQC has an internal regulator, being able to throttle the speed made the experience a dream. ( The 114GQC is also highly recommended )

I've used the 3/8 version for several years and been very happy. I live on the coast of Maine so corrosion is a major issue on newer vehicles. I also work on older 50 or more year old cars for my own pleasure. You obviously want to use impact sockets or bits, and don't start out full bore on the impact. I have the Snap on PH3050 and turn it way down for smaller fasteners. It really works to shake very stuck nuts and bolts free. Use a wrench to turn it as you finesse the air hammer. I finally got the 1/2 inch to use larger sockets without needing an adapter, but the 3/8 has done everything I've ever tried. Also It works well with impact hex or torx bit sockets and I use a 5/16 impact socket with screwdriver bits to shock things loose. Don't use non-impact, I used a non-impact allen socket on a brake rotor screw and it destroyed it, fortunately it was warrantied. This is a great time saver and Mayhew is a great company. Don't buy knock offs or you'll probably break them before your bolts break free. I reach for this more often than the torch or induction heating tool. Works great and I haven't snapped bolts which becomes a major hassle. It also doesn't take any room so things like recessed lug nuts/bolts can be accessed as long as you can get a socket on it.

Very good quality and very handy. I use it mostly on aftertreatment sensors that I can't bust loose with a wrench or regular socket. You can beat on this thing all day and it will hold up.

I bought the 1/2" drive about six months ago and I just added the 3/8" to my wishlist. The purpose of this tool is to get a socket or socket bit on the end of your air hammer and turn it with a wrench while you "shock" it. The difference between this tool and an impact wrench is that the user has more "feel" and can apply the torque independently of the shock for removing smaller or fragile fasteners. I operate the air hammer with my right hand and use my left hand to apply light torque on the wrench at first and then gradually increase the torque until the fastener breaks loose. In contrast, an impact wrench bangs and spins hard and fast so you might strip or snap the fastener in a fraction of a second. I'm a bicycle mechanic so I use this tool most often for loosening stuck T25 Torx head bolts that secure the brake rotor to the hub. I've also used it with a 1" or 1-1/8" socket to tickle headset bearings that were sweat-skanked into the frame so they just lift out in one piece. If you already have an air hammer then this is a great inexpensive option to get more use out of it and maybe save the day. It works especially well for shallow "female" fastener heads like Phillips, Torx, Allen that need a little finesse to remove. My only complaint is that there is no hog ring or spring ball so the sockets just fall off of the tool.

I have used several devices like this in commercial aviation for removing inspection plates, screws etc in commercial airliners. This tool is known as a "screw knockers", "old man" and other weird names. I could not find mine so I bought this one. I am not disappointed. I read that some users complained about this "old-man" not having a retaining ball and the socket, etc., would fall off. These tools are designed to take a LOT of abuse and a ball-spring-detent would just make it weaker, (I have never seen one with a ball detent). In aviation we always wrapped a small half strip piece of masking tape around the end (shown in photos), and Wala! The socket stays on. I hope this is helpful. By the way, the shank is 10.05 mm or .3975" . I used this in a .401" shank 4X rivet gun and pounded the stuffings out of it. It held up well. A rivet gun hits much slower but way harder then a air hammer. The knocker held up without any problems, however my 40T torx did not, no fault of the knocker. Yes, I would recommend this to a friend. Good value for a 3/4" drive screw knocker.

It comes in handy to help prevent stripping out brake rotor set screws. Just grab a 19mm wrench and a 3/8” T30 socket, you’re good to go. Makes quick work, and you don’t risk stripping out the fragile screws.

Six stars! A must have tool. I’m constantly having to remove service panels on equipment with rusted on Allen drive hardware. Easy to strip. Haven’t stripped one since buying this tool.

I said the product did not work in my snap-on air hammer but the quick disconnect was wore out and that was the problem. Sorry for the inconvenience

Outil merveilleux!!! Bel addition a mon coffre d outil.

Only way to get seized glow plugs out of a Duramax, once motor is hot and with the use of this tool working the glow plug back and fourth and then it’s out!

Great tool use it for removing exhaust manifold bolts, only wish is had a retainer to keep the socket on when going from bolt to bolt, bought both the 1/2 and 3/8 versions

Great tool to have in your box. It’s a same not to have a socket retainer on the square drive, but if your old school you’ll remember the paper trick for not dropping nuts and bolts out of your sockets so this isn’t a problem. Fair price.

It does the job.