Do the cutting dies of a knock out set wear out? I have a couple Ratchet knock out sets and sometimes they seem to cut harder than other times. I have replaced a couple draw studs as they strip out and the bearing but never a die. I do not use them every day but have used them a lot over the years. Do they get dull? I am assuming it is something I need to replace and not repair/sharpen?
Greenlee Knock out sets
- Thread starter arnettda
- Start date
yes. The cutting edge gets dull.
I have replaced several over the years.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
They do get dull especially when cutting heavier material. They do cost $$. I am sure a sharpening shop could tune the up. Is it worth it?? I don't know.
Jpflex
Electrician big leagues
- Location
- Victorville
- Occupation
- Electrician commercial and residential
What tool do you use to sharpen cut points?
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Since sharpening means removing material, and you never want to decrease the outside diameter, I imagine you would use a flat grinding surface on the flat facets of the punch, restoring the points and the round cutting edges. The edges of the cups can probably also be sharpened
rambojoe
Senior Member
- Location
- phoenix az
- Occupation
- Wireman
It would need to be (the edge) retreated... kinda not worth having it fail half way in a piece of expensive gear..
Store them correctly (business side up in the cup) or tape up the edge.. i tape up my stepper bits in my bag to keep them sharp- works great.
Store them correctly (business side up in the cup) or tape up the edge.. i tape up my stepper bits in my bag to keep them sharp- works great.
- Location
- Bremerton, Washington
I used to get my uni bits sharpened, so it’s probable ko punches can be done
rambojoe
Senior Member
- Location
- phoenix az
- Occupation
- Wireman
Uni bits especially i tape the edge since it bangs around in the tool bag-
I also stopped loaning out these things, and the tko cutters (which i love..)
They are always returned black and blue or w/gypsum dust on em.. ggrrrrr.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
I have sharpened uni bits with a Dremel tool in a pinch.
Most likely anything can be sharpened the question is it worth it. Uni bits and KO punches are $$$$
rambojoe
Senior Member
- Location
- phoenix az
- Occupation
- Wireman
Uni bits at good ol H.F. sorta are ok...same w/drill bits. Screw it, guys destroy them anyways.
Then there is that small possibility that the good ones are made in the same..
Country...
Then there is that small possibility that the good ones are made in the same..
Country...
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
The country of origin is not as important as the material they are made of. Cheap steel is only worth it if you sharpen your own.
I gave up buying American Vermont 'plain' bits. Cobalt bits are cheaper than time lost with dull and broken bits. But I rarely drilled anything larger than 5/8". My hole saws were carbide cutters.
rambojoe
Senior Member
- Location
- phoenix az
- Occupation
- Wireman
Yup, carbide- the ideal tko's. The thing is... the pilot on the carbide is high speed have at it. The carbide part is low speed- and fragile. Thats how my guys destroy em... im clear on good and bad, believe me! Just a tip- the hb uni steppers are pretty good lately- and cheap.
Has anyone noticed that all ceiling fans, regardless of brand are all intertek? Look at the sticker next time... kinda weird.
I spend enough time w/sharpening our kitchen knives...no more xtra work plse!
The pink dremel chainsaw tuning bit works very well though. Ill agree on that.
Btw, sometimes ace is good on pricing...
Sometimes.
Had several 1/2, 3/4 & 2" Greenlee dies wear out probably after several thousand uses. Went with slug splitters. Had what look almost like stainless steel 1/2, 3/4 & the one for Allen Bradley & other start, stop buttons & panel light that are rugged. Always used a little bit of 3 in 1 oil on all KO'S. Found made in USA carbide hole cutters to be the fastest if you only had a few holes to make. Do not purchase the garbage DeWalt hole cutters made in cheating china that graingers sells. Paid over $60 for a 11/8" ( for 3/4" conduit ). Cuts a clean hole but takes three times longer then my old Klein carbide hole cutter.
I find that most guys don’t realize they need to follow manufacturer’s speed requirements for hole saws and carbide hole cutters. They just put the drill on the fastest possible speed and let it rip. Then while cutting they wonder why it smells like it’s burning and after the bits come out all black and blue and get dull quick. They get them way to hot and they edges lose their heat treat and hardness and get dull quick after that. When used at proper speeds hole saws hole cutters and unibits will last a very long time. I have a Greenlee step bit that’s 30 years old and still deadly sharp. Never been sharpened
You are so correct that speed kills hole saws & unibits. Still have the stubby Greenlee unibit in small round tube that came with my hydraulic KO set 40 years ago. Had one of the tool & die shops I do work for sharpen it once on a surface grinder. You even have to be carefull when using unibits, hole saws or the think its 135 degree drill bits when drilling into stainless steel. If you drill too fast it work hardens that area making it several times harder to punch thru.
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Stainless is nasty to work with- go slow, take deep cuts, use plenty of coolant/lube (WD40 seem to work quite well, and everyone has it).
For speeds... checking a handy chart for a 1/4" drill-
"free cutting steel" is 2300rpm, but cast iron is 1500 and SS is around 1000. Go up to 1/2" and it's 1000, 750, and 500 (rounded down).
Keep the speed down!
For speeds... checking a handy chart for a 1/4" drill-
"free cutting steel" is 2300rpm, but cast iron is 1500 and SS is around 1000. Go up to 1/2" and it's 1000, 750, and 500 (rounded down).
Keep the speed down!
We drill quite a bit of Stainless plate in SEL relay cabinets.
I can’t get my guys to understand to go slow. Slow,slow,slow…
SS wears out knockouts pretty fast also
kwired
Electron manager
- Location
- NE Nebraska
Intertek is the NRTL that listed them.
rambojoe
Senior Member
- Location
- phoenix az
- Occupation
- Wireman
Well that explains it... they have it right by the model number so i wrongly assummed. We got 14yrs out of the fans so i was trying to get the same brand- which isnt labeled anywhere it seems..
14 yrs on all day everyday btw...
Edit, i just looked at the pics of the stickers i took, they all say hongkong appliance co. funny enough...