Knife from mechanic hacksaw blade help.

S

s_gaitandjiev

Joined
Dec 7, 2016
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6
Hi guys ive been grinding two knives for the last few days with my bench grinder and im pretty happy with the shape. But now ive hit a snag.Im using some old mechanic hacksaw blades ive found. They are about 2-3mm thick. Today i tried to drill holes for the grip pins but no drill bit want to go through this metal. I only managed to go through 1/4 it the tang with a diamond coated bit but after that it stopped doing anything. I tried using HSS drill bits, i thinl they are titanium coated bc they are yellow and i think it said so on the box. So any ideas on how to drill through this and if not is there a sure way to fix the grips without pins ?

PS one of the knives is a kitchen knife so can i skip the pins and just use epoxy
 
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Carbide bits, or you need to anneal the steel. Try a masonry bit, they have carbide tips. I've used a diamond bit from the tile section of a hardware store. Not ideal, but it works,
 
I use Strongarm drill bits. There is craplittle those wont cut thru.
But... the resulting hole is not highly accurate.
There are other options, cobalt for example.
Mind your RPM & use lots of coolant.
Good luck.
 
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I wouldn't reply JUST on epoxy. As for drilling the holes you might get one or two holes with a cobalt bit, but I'd just get a carbide tipped masonry bit from the nearest big box hardware store, and you should be able to get some holes in the tang pretty easily. The holes will be a little bigger than the stated size, but as long as you have a tight tolerance on the pin holes for the scales, you shouldn't have a problem.
 
Hidden tang. That's what I've resorted to for HSS recycled blades.
 
PS guys the steel isnt stainless so what a good way to protect the blade from rusting that wont be bad for using on food.
 
s_gaitandjiev said:
PS guys the steel isnt stainless so what a good way to protect the blade from rusting that wont be bad for using on food.
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Wipe dry after use. The steel will patina, and the patina will protect the blade from rusting. I've never oiled a blade. Ever.
 
Ok guys after 4 hours of driling i only got 3/4 of the way and after that its imposible. I used a new bosch masonry bit and even sharpened it. This is one crazy steel its impossible i lubricate with wd40 but its now working. What could be the problem
Ps i tried a cobalt bit and it was even worse it can start a hole or take of material from the old hole
 
No need to sharpen the carbide tipped masonry bit. Just make sure you're running at a moderate RPM with a constant pressure.
 
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s_gaitandjiev said:
Hi guys ive been grinding two knives for the last few days with my bench grinder and im pretty happy with the shape. But now ive hit a snag.Im using some old mechanic hacksaw blades ive found. They are about 2-3mm thick. Today i tried to drill holes for the grip pins but no drill bit want to go through this metal. I only managed to go through 1/4 it the tang with a diamond coated bit but after that it stopped doing anything. I tried using HSS drill bits, i thinl they are titanium coated bc they are yellow and i think it said so on the box. So any ideas on how to drill through this and if not is there a sure way to fix the grips without pins ?

PS one of the knives is a kitchen knife so can i skip the pins and just use epoxy
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I use this on M35 at 67Hrc , this is much faster than any diamond and very cheap :thumbup:

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Plasma cutter, zap done.
But in your situation I would do this. Wrap a paper towel around the blade area and soak with water. Then using a torch heat the area your going to drill through till its red/orange the quickly drill it while it's still red hot. The drill will drill it like butter while red hot. But being a unknown steel who knows you might be able to just heat the areas and let cool and it will be soft enough to drill. But drilling while red hot has ALLWAYS worked for me.
 
timgunn1962 said:
What was the machine you used to drill it with? Handheld or a drill press? And what speed?
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first i tried with a drill press the with a handheld drill at about 2800-3000 rpm. I swear i was putting crazy amounts of preasure and it wouldnt go through it just stopps drilling at one point. Its like the drill bits dont have an edge to cut the holes. At one point it seems like the bit only polishes the surface but doesnt take of any material
 
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the problem here is you are trying to use a "High Speed" drill bit to cut a hole in "High Speed" steel.
even the "Cobalt" ones are still High Speed steel with 10% cobalt added.
you must use Carbide to make the hole or grind a hole in . a masonary/cement drill can do this but the tip is not well designed for cutting metal.
if nothing else try a carbide burr with a round nose on it. it will make a hole .
 
ok i finally managed to drill through the damn thing with those bits that are made from bonded abrasive particles like a bench grinder disk. PS im not sure the steel is hss. Im from Bulgaria and the hacsaw blades are more than 20-30 years old, probably old russian ones or something
 
s_gaitandjiev said:
ok i finally managed to drill through the damn thing with those bits that are made from bonded abrasive particles like a bench grinder disk. PS im not sure the steel is hss. Im from Bulgaria and the hacsaw blades are more than 20-30 years old, probably old russian ones or something
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Like this one :) Rear left and rear right are excellent for this kind of work ....You can drill in any known steel :thumbup: But you need speed, more speed the better ... 20000 rpm is right .

6rr0yd.jpg



Now , where is the picture of knive :)
 
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yeah i used exactly those to drill through but they wear out very quckly, this time i used them on a dremel like drill but i cant seem to find the rpm
here are the two knives please dont laugh :D
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