Best way to apply m2.5 taps in 1.5 mild?

[julianf]

I need to apply a whole load of M2.5 taps into 1.5mm mild steel.

Each unit has 20 or so holes, and is a pre-existing part, so I need to have a very small error rate.


The only way I ever do tapping is using the drill press to hold square and turning the chuck by hand, but that's tedious for a handful of threads, let alone 100s.

I'm happy to buy a machine. Would have to be the slim side of £1000 though.

 

[nickk]

Don’t know if you can get the size,but I use the Hall hexbits that fit in 1/4”holders in a battery drill,saved me a lot over the years.
Reca also do similar but form part of a drill bit.

 

[julianf]

Would I ever get them anywhere close to square in 1.5mm with a hand held?

 

[123hotchef]

depends how many beers you have had, the smaller sizes snap easily also in a hand held drill ask me how I know

 

[Aff]

I've had to do similar and used one of the Indexa tapping heads, they are about 200 quid.

Indexa M2-M7 Tapping Head Sets, Collets X Arbor (J| at Zoro

Indexa - M2-M7 Tapping Head Sets, Collets X Arbor (JSN7-17) available at Zoro.co.uk - UK's Leading Supplier of DIY Tools and Supplies'

www.zoro.co.uk

I used it on the drill press at about 900rpm, as long as the holes are prepped properly (correct pilot size and a lead in chamfer) and you use some decent cutting fluid you'll have no issues.

 

[julianf]

I've had to do similar and used one of the Indexa tapping heads, they are about 200 quid.

Indexa M2-M7 Tapping Head Sets, Collets X Arbor (J| at Zoro

Indexa - M2-M7 Tapping Head Sets, Collets X Arbor (JSN7-17) available at Zoro.co.uk - UK's Leading Supplier of DIY Tools and Supplies'

www.zoro.co.uk

I used it on the drill press at about 900rpm, as long as the holes are prepped properly (correct pilot size and a lead in chamfer) and you use some decent cutting fluid you'll have no issues.

That price looks good for me, so I'm interested...

You mention lead in - the pilots will be laser cut, so nice and clean, but no chamfer.

Will that be an issue for me?

Thank you

 

[Hood]

Decent quality spiral point tap in a battery drill. Just make sure you hold the drill steady when you flick to reverse as small taps snap easily.

 

[123hotchef]

will it work harden the steel being lazer cut

 

[julianf]

will it work harden the steel being lazer cut

Who knows, but I kind of doubt it.

The laser is such a localised heat. The moment it isn't localised the finish would fail. So, possibly the very surface, but it would be such a thin layer.

But, in truth, I don't really know, but my feeling is no.

 

[mike os]

Tapping head and good quality spiral point machine taps

Unless you can get them to cut you a sample to assess hole accuracy I would suggest running a drill into the hole to ensure it’s accurate, probably get lasered .1 to .2 undersized too. Laser is very good and quite accurate but you don’t have much room to play, at that size .1 is a lot of thread to lose.

you could countersink by hand which helps getting started but personally I wouldn’t think it needed.

 

[Aff]

That price looks good for me, so I'm interested...

You mention lead in - the pilots will be laser cut, so nice and clean, but no chamfer.

Will that be an issue for me?

Thank you

I had to do about 2000 M3 holes in 2mm lasered mild, the lasered hole was good but not perfect, I found if you chased the hole out with the correct size drill they tapped great but was a pain.

Kissing the holes with a countersink in a battery drill achieved the same result and was far quicker.

I did the first few hundred with a tap in a hand drill and snapped 4 taps as I lost concentration.

With the tapping head I didn't snap a single tap in the remaining 1800 holes.

And as above a decent quality spiral point makes life more bearable.

 

[julianf]

I had to do about 2000 M3 holes in 2mm lasered mild, the lasered hole was good but not perfect, I found if you chased the hole out with the correct size drill they tapped great but was a pain.

Kissing the holes with a countersink in a battery drill achieved the same result and was far quicker.

I did the first few hundred with a tap in a hand drill and snapped 4 taps as I lost concentration.

With the tapping head I didn't snap a single tap in the remaining 1800 holes.

And as above a decent quality spiral point makes life more bearable.

Thank you. This is just the sort of information I need.

I get the parts Lasered and cnc folded, as I can't do that myself, and then I do the finishing here. Which is normally just riveting and painting, but this job requires tapping also.

Tapping increases the price by about a tenner a unit if I get the folding place to do them, so, providing I can do more than one an hour, I'm better than minimum wage doing it here.

I've just looked, each unit has 34 holes to tap.

So if I can do two an hour, or roughly one hole per min, take a £10 / HR wage and put £10 / HR towards the toll cost, my break even on outsourcing would be 20hrs / 40 units. As in I'd work for 20hrs at minimum wage but the tool would be paid off in the process.

I'd assume 1 tap per min would be feasible enough? I mean obviously more than feasible on a run, but taking into account setup and problems etc?

 

[Seadog]

10 seconds a hole if you're trying. That's about 15 per hour. Also, probably easier to tap before folding.

 

[julianf]

10 seconds a hole if you're trying. That's about 15 per hour. Also, probably easier to tap before folding.

Yep, but that complicates things with transport back and forth, so ill do them after folding. Its just a simple rectangle shape though, so it shouldn't complicate things that much. Slight loss of stability, as i wont be tapping direct onto the table, but it wont be that much different.

So long as the time is under my worst case estimate (which included setup and resolving screw ups) then im good.

 

[JMS1972]

Yep, but that complicates things with transport back and forth, so ill do them after folding. Its just a simple rectangle shape though, so it shouldn't complicate things that much. Slight loss of stability, as i wont be tapping direct onto the table, but it wont be that much different.

So long as the time is under my worst case estimate (which included setup and resolving screw ups) then im good.

Can you knock up a wooden frame to fit inside to support it whilst tapping?

 

[Aff]

Yup, definitely worth making yourself a little jig to position the part and catch the kickbar on the tapping head so you can use both hands.

 

[julianf]

Can you knock up a wooden frame to fit inside to support it whilst tapping?

The part is very similar to one of these -

The holes I need to tap are around that internal rim.

It's folded in 1.5steel and the rim is actually a bit narrower than the one in the photo.

Do you think the deflection / vibration will be an issue? I'd assume not, but if I knew, I wouldn't be asking! : )

 

[awemawson]

John Stevenson used to use a tapping head mounted on a set of articulated arms that would move all over the base and raise and lower, but keep the tapping head vertical. Arms a bit like a vertical pantagraph.

 

[julianf]

Oh, and to give scale, the box is 3" deep.

The whole job is 3" X 7" X 17", so small enough to get under a standard drill press. I'm only tapping that lip, nothing else.

 

[JMS1972]

The part is very similar to one of these -

The holes I need to tap are around that internal rim.

It's folded in 1.5steel and the rim is actually a bit narrower than the one in the photo.

Do you think the deflection / vibration will be an issue? I'd assume not, but if I knew, I wouldn't be asking! : )

I don't know it's probably one of those try it and see you are most like to get deflection in the middle of the long edges so maybe just wedge a bit if wood there if its needed but I wouldn't think you need much force to get the tap started ..