Needs Pictures: 0
Results 1 to 15 of 20
Thread: Sharpening a Centre Punch
-
12th Jan 2021, 11:28 PM #1Most Valued Member
- Join Date
- May 2011
- Location
- Murray Bridge S Aust.
- Age
- 71
- Posts
- 5,942
Sharpening a Centre Punch
To get a nice consistent point on my Centre Punches, I put them in the DP at around 600 rpm, and use a small angle grinder held at the correct angle, for a short period.
Taking off the mushroom head can also be done on the DP, with good results.
KrynTo grow old is mandatory, growing up is optional.
-
13th May 2021, 09:42 PM #2Most Valued Member
- Join Date
- Oct 2010
- Location
- melbourne, laverton
- Posts
- 1,910
Cool Merrill try that
-
14th May 2021, 12:51 AM #3Member: Blue and white apron brigade
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 7,182
Both my spring loaded centre punches won't run true in my drill press, while the non-spring loaded ones have square shanks
-
14th May 2021, 05:39 AM #4
Hi Bob, Guys,
The spring loaded ones, I remove the punch, its also easy to make new ones for them !
I sharpen my centre punches in the lathe using a Dremel in the tool post. About the only time that I've used the drill press is to hold a short length of silver steel when I've already made the point by turning and I'm heating it to harden the tip. I spin the silver steel and then get it red with a cooks torch, then plunge into a tin of oil ! Usually the cooking oil that the wife throws out of the chip pan, smells of chips... mmm. I've made several transfer punches this way.Best Regards:
Baron J.
-
14th May 2021, 08:35 AM #5Member: Blue and white apron brigade
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 7,182
Useful tip about removing the tip on a spring loaded punch to sharpen it.
To sharpen tips on stuff that fits in a cordless drill I spin the tips against an unsupported part of a Linisher belt.
Sometimes I sharpen TIG tips against a diamond wheel.
The tips on the tines of this wool carding comb were made this way.
The tines are pieces of TIG rod
IMG_4685.jpg
Which is why I wanted to get the all the same length.
colletEnd.JPG
-
16th May 2021, 05:29 PM #6Mechanical Butcher
- Join Date
- Oct 2004
- Location
- Southern Highlands NSW
- Posts
- 1,894
Note that grinding should be parallel to the axis of the punch, not across it.
-
16th May 2021, 07:46 PM #7Most Valued Member
- Join Date
- Nov 2007
- Location
- melbourne australia
- Posts
- 3,228
-
16th May 2021, 08:00 PM #8Most Valued Member
- Join Date
- Nov 2008
- Location
- North Brisbane. Qld. Australia
- Age
- 70
- Posts
- 1,511
-
16th May 2021, 08:37 PM #9Member: Blue and white apron brigade
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 7,182
-
17th May 2021, 09:30 AM #10Mechanical Butcher
- Join Date
- Oct 2004
- Location
- Southern Highlands NSW
- Posts
- 1,894
I read it in a few different places, that grinding a centre punch should be such that any grooves (tiny but there) should be towards the conical tip.
I thinks it's to minimise the effect of any stress risers weakening the tip.
-
17th May 2021, 05:29 PM #11
Hi Guys,
I have a centre punch that does not have a conical point !
Instead it has a three sided pyramid shaped point and is quite sharp compared to the conical point ones. Its also very easy to find the intersection of scribed lines with it. You can easily feel the scribe mark.Best Regards:
Baron J.
-
18th May 2021, 11:11 PM #12Senior Member
- Join Date
- Mar 2013
- Location
- Mt Pleasant SA
- Posts
- 126
-
25th Jul 2021, 01:29 PM #13Member
- Join Date
- May 2020
- Location
- s.w. sydney
- Posts
- 53
-
25th Jul 2021, 10:03 PM #14Gear expert in training
- Join Date
- Aug 2008
- Location
- Melbourne
- Age
- 34
- Posts
- 1,075
You want to make it consistent so it's easier to line up on your scribe lines. Nothing wrong with a bench grinder at all
Gear cutting specialists and general engineers www.hardmanbros.com.au
Fine pitch gear cutting from 0.1 Module www.rigear.com.au
-
26th Jul 2021, 12:33 PM #15Member
- Join Date
- May 2020
- Location
- s.w. sydney
- Posts
- 53
Similar Threads
-
Automatic Centre Punch
By Twisted Tenon in forum METALWORK GENERALReplies: 11Last Post: 27th Sep 2017, 01:27 PM -
Sharpening Spring Loaded Centre Punch
By Fuzzie in forum METALWORK GENERALReplies: 7Last Post: 29th Nov 2015, 04:06 PM -
Optical centre punch for 'simonl'
By Steamwhisperer in forum METALWORK GENERALReplies: 53Last Post: 30th Aug 2012, 06:11 PM -
Optical centre punch
By morrisman in forum METALWORK GENERALReplies: 5Last Post: 9th Aug 2012, 01:16 AM -
Centre punch mark magnifer
By neksmerj in forum METALWORK GENERALReplies: 15Last Post: 18th Jul 2007, 01:59 PM