Tap suggestions

[sundown57]

I have a job to tap 100 or so 1/2-13 blind holes into both cold roll and hot roll. ive been getting taps from McMaster but lately, they don't seem to be very good quality and cut hard. Anyone know of a better name brand than what they sell? thanks

 

[markba633csi]

Widia/GTD is the best brand I've used- with the golden coating
Zoro tools has a good selection

 

[Asm109]

I get a lot of taps from McMaster and a lot of time they are GTD or widia brand.

 

[sundown57]

I get a lot of taps from McMaster and a lot of time they are GTD or widia brand.

yeah same brand I get. maybe I just got a couple of rejects ..

 

[woodchucker]

so for blind holes are you using spiral flute taps?
if they are hard to cut with, have you tried going up in drill bit one size so from a 27/64 to 7/16, or a 10.8mm?

 

[mksj]

Guhring, OSG, Nachi are usually considered to be quite good, I assume you are already using a spiral flute tap. Suncoast Tools is a very good source of tooling and at very fair pricing. OSG there are a lot of choices...

Blind Hole Inch Green Ring, Universal Applications, Steels High Performance Cut Taps

www.guhring.com

https://www.suncoasttools.com/crm/ItemPage.aspx?ItemNumber=9039770127000&VendorNumber=GUHRING

https://www.suncoasttools.com/crm/ItemPage.aspx?ItemNumber=800.500013+4408H3+49&VendorNumber=GUHRING

OSG Spiral Flute 3-Flute Taps | Zoro

Shop for OSG Spiral Flute 3-Flute Taps on Zoro.com. With 1000s of brands and millions of products, you're sure to find what you need.

www.zoro.com

 

[sundown57]

so for blind holes are you using spiral flute taps?
if they are hard to cut with, have you tried going up in drill bit one size so from a 27/64 to 7/16, or a 10.8mm?

i am using spiralflute. I have not tried a larger hole.

 

[ChazzC]

i am using spiralflute. I have not tried a larger hole.

Little Machine Shop recommendations (55% - 60% for steel):

 

[projectnut]

Is this a job for a customer or for a personal project? If it's a customer job, I would ask some particulars about what the components are being used for. The industry standard for tapping holes is a 75% thread engagement. That is achieved by using a standard drill for the size tap being used and an H3 tap.
The H designation defines the clearance between the crown of the threaded fastener and the root of the tapped hole for imperial threads. The D classification denotes the clearance between the crown of the threaded fastener and the root of the tapped hole for metric threads. For each number above 0 the clearance increases by .0005". An H1 tap would have a clearance of .0005" while an H3 tap would have a clearance of .0015".

Standard H designations go up to 12. Those above 3 or 4 are generally used to allow for proper clearance when parts are anodized or coated with other materials after tapping.

 

[LaughBlacken]

I feel your frustration with those taps! For better quality, consider brands like Irwin, Greenfield, or OSG. They're known for durability and efficiency. Good luck with your project!