Mike C.
Diamond
- Joined
- Nov 25, 2004
- Location
- Birmingham, AL
Had a 16 hole bolt circle to drill and tap on the radial drill this week. Apparently nobody on this planet makes a Morse Taper 4 tap driver for a 20x2.5 tap?
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20mm tap driver 4MT Unobtanium?
- Thread starter Mike C.
- Start date
- Replies 15
- Views 1,306
Limy Sami
Diamond
- Joined
- Jan 7, 2007
- Location
- Norfolk, UK
Mike, what's the dia of the tap shank?
Or brew your own (with 4 grub screws ro bear on the sq') MT4 Morse Taper 4MT Soft Blank End Arbor Lathe Mill Drill Tang Type 32 x 48mm
Or brew your own (with 4 grub screws ro bear on the sq') MT4 Morse Taper 4MT Soft Blank End Arbor Lathe Mill Drill Tang Type 32 x 48mm
L Vanice
Diamond
- Joined
- Feb 8, 2006
- Location
- Fort Wayne, IN
Perhaps you could use a 4MT tanged shank ER collet chuck. There is such a thing as ER tap collets with internal squares, but I guess you have to watch the square size to match your tap.
Metric taps are made to several different standards, so the shank diameter and square size for a given thread size can vary. In the USA, ANSI shanks are common, but ISO, DIN and JIS shanks will be different.
Standard Tap Dimensions (ANSI Shanks) - Tapmatic Corporation ANSI taps let metric taps fit common USA size collets.
Standard Tap Dimensions (DIN 374) - Tapmatic Corporation
Thread standards and tapping hole tolerances
Larry
Metric taps are made to several different standards, so the shank diameter and square size for a given thread size can vary. In the USA, ANSI shanks are common, but ISO, DIN and JIS shanks will be different.
Standard Tap Dimensions (ANSI Shanks) - Tapmatic Corporation ANSI taps let metric taps fit common USA size collets.
Standard Tap Dimensions (DIN 374) - Tapmatic Corporation
Thread standards and tapping hole tolerances
Larry
JS
Stainless
- Joined
- May 5, 2005
- Location
- Republic of Arizonia
cyanidekid
Titanium
- Joined
- Jun 4, 2016
- Location
- Brooklyn NYC
Big Kaiser drill tapper QC system comes in MT 4, but the catalog doesn’t seem to have metric tap holders, but I’d bet they make them. It’s a rubber clutch type quick change holder, and they are a bit expensive new. Comes in different sizes.
Mike C.
Diamond
- Joined
- Nov 25, 2004
- Location
- Birmingham, AL
Thanks, JS! Nailed it. I can sleeve it to 4MT. Hand tapping 16 holes was a real party yesterday... and of course it's a rush job.
David_M
Hot Rolled
- Joined
- Sep 30, 2014
- Location
- Midway, GA, USA
COLLIS #70401 3/4" to MT4 Heavy Duty Tap Driver | eBay
COLLIS #74452 3/4" Tap Size to MT4 Split Sleeve Tap Driver | eBay
3/4" shank and square are supposed to be the same as M20 (according to the chart I referenced), but I can't confirm that until Monday.
Tap Shank and Drive Square dimensions (tools-n-gizmos.com)
COLLIS #74452 3/4" Tap Size to MT4 Split Sleeve Tap Driver | eBay
3/4" shank and square are supposed to be the same as M20 (according to the chart I referenced), but I can't confirm that until Monday.
Tap Shank and Drive Square dimensions (tools-n-gizmos.com)
dont forget din 357.
Mike C.
Diamond
- Joined
- Nov 25, 2004
- Location
- Birmingham, AL
Nope, a 20mm tap has a 15mm shank. It will not go in a 3/4" driver. I have most every tap driver over 1/2" and nothing fit the 20mm. A 19mm tap fits a 3/4 and a 22mm fits a 7/8".
cyanidekid
Titanium
- Joined
- Jun 4, 2016
- Location
- Brooklyn NYC
I've learned quite a bit from this thread myself.
If you look at the table in post 3# from Larry, it's all right there, an ANSI 20MM tap has the same shank and flats as an ANSI 13/16 tap (NOT a 3/4), .652 shank, .489 across the flats, nominal.
ANSI metric taps are the most common type generally available in the US (as GarW said). all you need to do is order a 13/16 ANSI holder if your tap is .486-.489 across the flats ANSI, however going by your post 10, if its 15MM, I don't know what that is, so you probably need to get an ANSI tap as well, easy enough.
It's a bit of a mess as far as metric tap standards go with ANSI, ISO, DIN 374, DIN 358 whatever, and JIS. I didn't get as far into the weeds as comparing the latter 4, does anyone have a handy reference table for that?
David_M
Hot Rolled
- Joined
- Sep 30, 2014
- Location
- Midway, GA, USA
What's available from Collis (not including specials):
Tool Holders, Mill Holders, Collets: Collis Toolholder Iowa
It seems odd that the M20 can't be had in 4MT.
Tool Holders, Mill Holders, Collets: Collis Toolholder Iowa
It seems odd that the M20 can't be had in 4MT.
cyanidekid
Titanium
- Joined
- Jun 4, 2016
- Location
- Brooklyn NYC
David_M
Hot Rolled
- Joined
- Sep 30, 2014
- Location
- Midway, GA, USA
I guess no one is reading Larry's post, or my #12,
I was talking about just the Collis stuff on the list I linked to.
I looked at my stuff and this is what I have:
13/16 / M20 on compound and 3/4 in tailstock. And they are different.
the regular machne taps are either 371 for m3-m10 or 376 for m3-m30 (thin shank). hand taps are 352. 357 is obsolete (i use them for a set of tapping holders, hard to get). the other ones i dont even know what they are.
