Greensands | 14/06/2020 14:35:35 |
449 forum posts 72 photos | Hi - I have a number of standard threading dies in the usual ME sizes, some of which have a generous lead-in on the front face for easy starting and effectively a zero lead in on the reverse face which is very useful when threading up to a shoulder. With more recent purchases I notice that dies now now come with a lead-in on both front and rear faces making it a lot more difficult to continue the thread up to a shoulder. What I would like to be able to do is to grind off the lead-in from the back surface of these dies but in the absence of a surface grinder I am loathed to try any lash-ups for fear of having a disaster on my hands. What have been other peoples experiences in this regard and can anyone suggest a simple and safe way of achieving the desired effect. |
Mike Poole | 14/06/2020 14:48:12 |
![]() 3676 forum posts 82 photos | You could try machining a recess with a carbide tool, just facing off the back will compromise the dimple positions in the die holder. HSS will machine with a carbide tool and carbon steel should be ok as well. An alternative to threading up to a shoulder is to machine an undercut as would be required if screwcutting. Mike |
Pete Rimmer | 14/06/2020 14:49:19 |
1486 forum posts 105 photos | If I was compelled to attempt something like that, I would turn up a make-shift shallow die holder with a spigot to hold it in my battery drill. Mount the die in the holder, cobble up a rest and spin it in the drill whilst pressing it against the wheel of my bench grinder. |
10ba12ba | 14/06/2020 17:25:41 |
50 forum posts 24 photos | I have a few of these "double lead in " dies and as it happens I also have a surface grinder, so tomorrow i'll have a go at one. The only snags which come immediately to mind are that the dimples will the lie further back in the die stock (sort that out with a washer) and that the die will have become magnetised. H. |
Greensands | 14/06/2020 18:08:30 |
449 forum posts 72 photos | In the absence of a die having a zero lead-in on the back face a useful dodge I have found certainly for brass, is to tap the mating female thread into a short length of BMS Hex stock and face off the end to leave a well defined cutting edge. Works well with brass. |
BOB BLACKSHAW | 15/06/2020 02:50:23 |
501 forum posts 132 photos | That's a good idea Grensands, I suppose silver steel hardened off with two slots for a spanner would work on steel.I to have a number of ME dies with a double lead, I would like to know why they are made like this. Bob |
JasonB | 15/06/2020 07:09:40 |
![]() 25215 forum posts 3105 photos 1 articles | Unless you are threading to a very large shoulder then a Dremel can be used to hollow out the back of the die but leave the outer edge untouched so it still sits right in a diestock when used the right way round. You can then flip it around to finish the thread but I still tend to add an undercut or ease the female thread. |
Lainchy | 22/02/2021 10:29:13 |
![]() 273 forum posts 103 photos | I have exactly this issue on a very small part that requires 7/32x40ME... It only projects about 3/32nd - 1/8" Did anyone manage to grind or mill out the lead out from a carbon steel die? I notice also the post from Greensands... my brass hex external is 7/16. I'm guessing I could make just a 7/32x40 threaded bar, and silver solder a 7/16" brass nut to it. Got me thinking, but.... bit annoying that I can't just buy one as needed. Cheers chaps |
JasonB | 22/02/2021 11:04:21 |
![]() 25215 forum posts 3105 photos 1 articles | As I said above if shoulder is not too large a diameter than Dremel does the job, dimples stay in the right place and you still have a flat back face do die sits square in the holder |
Lainchy | 22/02/2021 11:40:29 |
![]() 273 forum posts 103 photos | Looks fine Jason. I'd wondered if you'd built some sort of grinding jig for the toolpost. Many thanks |
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