16 replies to this topic

[Gaz66]

Out of the generally available taps what are the better ones made from?
Carbon steel, hss, cobalt, tungsten steel etc etc
I'm thinking hss due to the cost but open to advice before I buy.
I'm after an M14 but they vary from £6 up to £35 🤔

[nicklouse]

Find a 3 piece set (May be two piece at that size)

1st 2nd and bottom. The more costly will most likely be for us in a machine rather than hand tools.

[stoneface]

https://www.theminif...-die-set/page-2

 

[Gaz66]

https://www.theminif...-die-set/page-2

I remember starting that thread but thought it was about a different element of tapping.
Oh the joys of getting old 😁
Looks like HSS then.

[Stu1961]

The best are those made from HSS, you can pick second hand ones up cheaper on eBay go for the better quality makes, Sherwood, Goliath, Dormer, Wurth, Presto, you need to use them in conjunction with a good quality cutting oil such as those made by Rocol or Sherwood, especially so if cutting a full/new thread.

 

Seems like a good deal (see link)

 

https://www.ebay.co....9SR-Cci86gZQ   

[Gaz66]

The best are those made from HSS, you can pick second hand ones up cheaper on eBay go for the better quality makes, Sherwood, Goliath, Dormer, Wurth, Presto, you need to use them in conjunction with a good quality cutting oil such as those made by Rocol or Sherwood, especially so if cutting a full/new thread.

Seems like a good deal (see link)

https://www.ebay.co....9SR-Cci86gZQ

That is cheap. I was looking at Presto taps and they were coming up at £35
(Just checked £35 was for a set)

Edited by Gaz66, 14 February 2025 - 02:51 PM.

[DeadSquare]

Even cheap taps can be satisfactory, provided, 1) The tapping hole is the correct diameter.  2)  You use all three taps.  3)  You use plenty of lubricant, and  4)  You take time and keep backing off every 1/2 or even 1/4 turn.

 

If you are struggling, something is wrong.  Stop.

 

When working with difficult materials, such as high  nickel alloys, I would often use all three taps, a succession of times.

[bikewiz]

I prefer TiN coated HSS. More expensive, but stay sharper longer and feel, to me, that they require less effort to tap. Nick's advice on the three piece sets is good, having each type makes your life easier. 

A simple thing I find with metric taps is subtract the pitch from the size to arrive at the tap drill size, so if you have a 14x1.5 bolt the tap drill size is 12.5mm, it's so much easier than fractional taps.

[nicklouse]

Some sets I bought in Germany.

[Gaz66]

Don't tell me the empty sections are snap offs 😳

[nicklouse]

Don't tell me the empty sections are snap offs

Nope.like I said some come as sets of three others as sets of 2.

[Shooter63]

I presume you are asking about a m14 tap as you plan to thread your oil ways, if so you need a plug tap otherwise known as a no3 or bottom tap, which is the one with hardly any feed, using one of those will allow you to feel when you touch the existing stop in the block, if you go in with a no1/taper tap you could quite easily go past this point ending up with the bung too deep. If possible set the block up on either a mill or a drill press, centre the hole you want to tap on the feed quill, fit a centre in the chuck, use the dimple in the end of the tap to keep everything square and off you go, tap away. The last thing you want is a thread of the piss.

Shooter

[Gaz66]

I presume you are asking about a m14 tap as you plan to thread your oil ways, if so you need a plug tap otherwise known as a no3 or bottom tap, which is the one with hardly any feed, using one of those will allow you to feel when you touch the existing stop in the block, if you go in with a no1/taper tap you could quite easily go past this point ending up with the bung too deep. If possible set the block up on either a mill or a drill press, centre the hole you want to tap on the feed quill, fit a centre in the chuck, use the dimple in the end of the tap to keep everything square and off you go, tap away. The last thing you want is a thread of the piss.

Shooter

Yes, that's exactly what I'm doing.
I just realised too after buying the wrong grub screws that the gallery hole thread ability (is that a term?) is dependent on the pitch of the grub screw.
I bought 2mm pitch which I believe is wrong.
I can't measure the gallery hole as the block is at the machine shop but from what I've read it's 12.5mm which would require a pitch of 1.5mm?

[weef]

You did start this thread asking for an M14 not M12, check what thread size you actually require before you commit to buying a tap set.

[weef]

Sorry read your post wrong, if the hole is 12.5mm dia then it should be an M14  1.5 thread pitch.