My knife broke!

Belstain · Jun 29, 2003

I broke my favorite bowie and I don't know how. I took it rabit hunting with me 2 weeks ago and it's been on the floor of the car in it's sheath ever since. well today I pulled it out and the tip was gone!!! about an inch from the end. I was crushed! I have no idea how or why it broke. It is a clean break just in front of where the temperline hits the back of the blade. There is no evidence of previous cracking or chipping near the break. it is about 3/32" thick and 3/4" wide where it broke. I am totally lost. I can't think how it could have broke like that. Any ideas?

Does anyone have any pictures of the grain structure that a piece of 1084 should have?

kile · Jun 29, 2003

Did someone ride in your car and step on the knife? Anything I put on the floor of my truck seems like it ends up broke. Sorry to here about the knife.
Kyle Fuglesten

Bruce Bump · Jun 29, 2003

Those must be some mean rabbits in your neck of the woods!

mete · Jun 29, 2003

Temper line ? Has it been differentially hardened ? If quenched and tempered it should be martensite with a uniform fine grain fracture. If differentially hardened there should be a a different structure and different fracture surface edge to back .

Belstain · Jun 30, 2003

yeah it was on the floor and lots of people have had their feet on it in the two weeks it was there. I just never thought that a blade could break from people stepping on it for some reason. now that I think about it though that seems kinda dumb

it was edge quenched but it broke at the tip where it was fully hard. grain is uniform and fine. the knife help up well through all my tests and a couple months of hard abuse. Even held up to some hard hits on a peice of rebar. after all that the damned thing breaks sitting in the car it just kinda blew me away.

I don't know if the rabbits are mean or not but they sure weren't iterested in playing with me. only saw one the whole day and he was sitting next to the road across from where a sheriff was parked.

John Andrews · Jul 1, 2003

Maybe the knife got caught in the seat adjustment rail while someone was adjusting the seat. I can see how that might break a blade with the rail and seat leverage. Sorry about your bad luck, guy.

Bruce Bump · Jul 1, 2003

I think you overheated the tip before quenching and someone stepped on it... or the rabbit did it when you wernt looking.

Burt Foster · Jul 2, 2003

If you examine the broken end, the grain should look like grey etched carbon steel. It can have hills and valleys, but it should be smooth to the touch. Get a small magnifying glass and check it closer. As long as it looks silky grey even under magnafication, the only other thing is that it was probably too hard. 1084 can get very hard (depending on austenizing temp and quench medium) and on a big knife should be tempered at probably 400-425 degrees to have that tip and edge strong enough not to break. Now that it's broken, you can do some more semi-destructive tests on it to see what else you can find.

Trace Rinaldi · Jul 2, 2003

I am thinking what Bruce B is thinking....

Belstain · Jul 2, 2003

I am thinking that Bruce is right. The grain looks about like 600 grit paper. I think it's time for me to get some professional instruction soon. Until then I'll just keep on keepin' on, trying to learn as much as I can on my own.