# Need 3/4" Weldon shank dimensions



## Cooter Brown (Jul 14, 2019)

I have been searching the internet for the dimensions of the 3/4" Weldon shank and all I can find is this page for end mill shank sizes....



			Machine Tool Shanks (Tapers)
		


I need the dimensions for a the shank on the end of a annular cutter.... I would just measure it if I had one....

I need the overall length of the shaft, the width and length of the flats.... I am grinding down a ER20A collet holder to fit a Mag Drill....





I hope one of you guys can help me out Thanks....


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## RJSakowski (Jul 14, 2019)

I don't think it is critical.  I measured an end mill and the flat was .080" deep x .46" long.


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## Cooter Brown (Jul 14, 2019)

RJSakowski said:


> I don't think it is critical.  I measured an end mill and the flat was .080" deep x .46" long.



I have plenty of 3/4" end mills I need the dimensions from a annular cutter....


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## Firstgear (Jul 14, 2019)

I have a full set of annular cutters and they all had the same size, 0.55”.  There is a slight taper from the top going to the base.  I provided the dimension of the base.   If I was making the tool and didn’t have access to the cutter, I would make it 0.50” just in case your cutter is different than mine.  I should note that I got this set from the Canadian distributor who got them from China.  I also have a full set of Milwaukee cutters that I haven’t used yet.

I really like these cutters, however when cutting they produce chips that are very small and come off the workpiece like a shower head with chips coming out in a 360 degree pattern of the work piece.[/QUOTE]


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## T Bredehoft (Jul 14, 2019)

I'm not sure its at all critical. The only propblem I see might be the depth of the cavity in the ER20A holder.


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## kd4gij (Jul 14, 2019)

Sounds like he is putting an ER20 collet chuck in his mag drill.  I would turn the shank to a snug fit, then push it in and center punch through the set screw hole and grind a flat there.


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## Video_man (Jul 15, 2019)

Cooter Brown said:


> I have been searching the internet for the dimensions of the 3/4" Weldon shank and all I can find is this page for end mill shank sizes....
> 
> 
> 
> ...


On my Chinese-made set, the shank from the top of the cutter to the end of the shank is 0.875 ins.  The sides of the flats are tapered, the inside (floor of the flat) measures 0.545.     The distance from the top edge of the floor of the flat to the end of the shank is 0.190.  The outside measurement of the flat including the tapered sides measures 0.672.  To use in my R8 mill I shortened a 3/4" end mill holder so that the set screw would line up with the flats.  The flats on end mills are further back than those on the annular cutters.  Hope this helps.


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## Firstgear (Jul 15, 2019)

I just used my 3/4” R8 collet when I used mine.  Never used a set screw.


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## mksj (Jul 15, 2019)

Typically 0.8-0.9" and can vary with brand and size of the annualar cutter. My dedicated weldong holder is bored to a depth of 0.95". Also the flat placement can vary a bit.  You should be fine using 0.85" length, the two 3/8" locking set screws are located 0.40" from the front edge. The width of the flats on the annular cutter are between 0.45 and 0.50"


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## pontiac428 (Jul 15, 2019)

For 3/4, the Weldon spec for the flat is .065 deep and .455 long.  The position of the flat depends on the tool having enough stick out past the holder, for example 1/16" from the end of the flutes to the tool holder.  Should be easy enough to do.


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## Cooter Brown (Jul 15, 2019)

I need the overall length of the shaft, the width and length of the flats....


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## Video_man (Jul 16, 2019)

Cooter Brown said:


> I need the overall length of the shaft, the width and length of the flats....


On my set, the flats are 0.455 wide, depth of cut 0.550.  Shaft from top of cutter to end of shaft is 0.875.  Mine appears to be made from a single piece of steel.  The Weldon shaft you show may be shorter by the amount the top of the cutter extends, but the overall length should work out the same.  Other info in my previous post.


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## Illinoyance (Jul 16, 2019)

If I understand correctly OP is modifying an ER20 collet chuck so it can be used in a mag base drill.    If he wants to hold annular cutters in the ER20 chuck it would be impossible.  The dimensions given here by other members should be sufficient to design the shank of ER collet chuck.  It might be appropriate to use a steeper taper on the flats to prevent pullout of the chuck.


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## Cooter Brown (Jul 16, 2019)

I am trying to put a ER20 collet chuck in my mag drill to hold regular drills.... Its much shorter than a drill chuck and holds better....



Illinoyance said:


> If he wants to hold annular cutters in the ER20 chuck it would be impossible.



Suck it... lol





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