The mystery of the broken wrench

I found this on the street between a nice apartment building and a chi-chi shopping center (Fidelity has its office in it), up the street from Trader Joe’s (I was on my way home from a shopping trip.). It’s 12-point. I measure 1 3/16" between notches, which makes it a 1" wrench. It’s broken by force. The last letter along the arm is A; the two letters perpendicular are KF. Assuming the Hulk didn’t get mad at it, it took something extreme to break it. I wonder if someone cranked his engine just a bit by hand (I’ve done that, with a metric wrench about the same size, to check the timing.), forgot it. It sounds exciting - why it lasted far enough to get to this spot, I can’t guess. What other thing do people have stronger than an automobile engine?

I’ve never broken a wrench outright, but I’ve badly damaged both the wrench & a fastener by adding a length of pipe to the wrench handle for extra leverage.

1 inch wrench? hmmm… I thought that meant it measured one inch from flat surface to flat surface, the surfaces being 180 degree apart. Does the geometry imply 1 3/16 corner to corner?

Reminds me, one thing that confuses diyers, a one inch wrench doesn’t fit a one inch bolt. The size of the bolt is the diameter of the threaded portion, unrelated to the dimensions of the bolt head.

That’s what I meant when I wrote ‘notch’. A 1-inch hexagon (face to face) is about 19/16-inch notch/corner to notch/corner. I’ve broken stuff I’ve tried to wrench too hard, especially with the ‘help’ of a scrap of pipe, never the wrench.

Can you look at the crack and tell where it started?

I had a screwdriver disappear in my diesel once. Found it years later laying against the exhaust manifold with the handle partly melted. Actually it was a much better grip with that modification. Stuff breaks or gets lost and eventually falls off. Who is going to go looking for very long for a broken box wrench? I’m still looking for my 12" crescent wrench though that I think I laid on the back bumper working on the hitch. It’s been about 25 years so someone must have picked it up. Got a black handle if you see it.

How do they make these? Stamped? Which is forged? Would think they were tough.

1 + 3/16? hmmm … I’m getting 1 + 5/32.

I can’t - got any tips?

I was curious as to how it broke.

Gotta be forged. Stamped wrenches are so flimsy they bend and tear instead. Have some for my bicycle.

Me too, but I’ve never seen wrenches in the 32nds and my measurement is imperfect. The blades of the caliper have a thickness that makes for incomplete measurement. I wrote ‘about’.

Here’s “How It’s Made”:

It’s not the wrench that’s measured in 32nds, its the measurement between opposite points of the hex pattern. I can see however that it would be difficult to measure the inside dimension of a 12-point socket to that sort of precision. It seems easier to measure across the points of a corresponding nut. No worries, just trying to understand where the 3/16 comes from.

I haves couple of oddball 32nd wrenches, never used

Look at the sides of the wrench at the break. Do you see any damage, like a dent or gouge? Also, look at the fracture face if it’s still undamaged. There might be discontinuities, like big inclusions or internal cracks that weren’t visible before the wrench broke. The last check is typically only useful shortly after the wrench broke. The longer it lies in the road, the more likely the fracture face will be damaged.

Actually I’ve got one just like it hanging on a peg. I must have bought it for something like struts or something. 1" on one end and 15/16" on the other. Master Mechanic brand made in Taiwan. The sticker still on it for $9.99. Also on the same hook is my curved 9/16 that was only used to change injector pumps on my diesel. I should try selling some of this valuable stuff.

I would have thought though that if this was on the engine bolt that the bolt would have broken. Maybe it was a left hand thread and put a 4 foot pipe on it going the wrong way. I dunno but I have the replacement if the guy needs it. $9.99 plus shipping. A deal these days.

My measurement of the wrench.

Why’d you get them?


I don’t see them. The broken face is jagged; it looks like enough force was applied to make it break. I’ve made smaller pieces of steel break; I can imagine the shock I’d get from breaking something this thick.

they could of been using a hammer to break what ever nut they were trying to get free. instead of hitting the edge they hit the face or on the corner. might of been enough of a shock to break it. just a guess.

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No good reason. I was working at a gas station in high school and spending money on the Craftsman catalog.

Maybe broke while being used outside in bitter cold or due to the metal being crystallized in that area for some reason.

I’d hang onto it but I’m also a pack rat. Those broken pieces of tools can end up very handy when making a specialty tool.

Post a picture of the fracture face. Someone might have used the wrench as a lever and broke it across the thin part of web rather than the thick part.

I’ve never gone after a wrench with a hammer, but I imagine it would take a lot of force.

In Albuquerque?

Hmmm… Isn’t it already crystallized? With enough something - heat, cold, banging - one can get the crystal structure to change. I can’t imagine somebody just wrenching doing enough of any of those.

I have all sorts of crap that’ll be useful some day. As soon as I’m done with my latest project I’ll throw it all away. If I paid myself minimum wage for the time I spent searching for one of these lost treasures I’d spend less if I went to the store and bought a new one. It is exhilarating to find them though, a poor man’s treasure hunt.

When I was struggling to take a good photo I remembered
the last time I used a camera, my parents’ Brownie on the elementary school trip to the state capitol in Annapolis.

That’s the best hypothesis so far, the most leverage the wrongest way.

Wrench + hammer = poor man’s impact wrench. Hold a little tension on the wrench, tap the wrench with a hammer. “Bust it loose” without busting your knuckles. I doubt that’s how that wrench broke, though. You’d reallly have to whack it. I figure y’all are on the right track thinking some sort of cheater pipe / leverage was involved.