RunRyder - Thread pitch for M3 metric screws

rrTV-PHOTO

New HD TV

HOME rrTV-PHOTO GALLERIES MY GALLERY HELP-FAQ

myHOME PM pmRR MEMBERS 630 ONLINE 44 EVENTS SEARCH REGISTER START HERE

1 page

303 views

POST REPLY

Ron’s HeliProz South	.	Century Helicopter	.	MTA Hobbies
	.		.

Tools and Field Equipment > Thread pitch for M3 metric screws

jrvander
Senior Heliman
Location: Mystic, CT

I just bought a set of Dubro metric taps today and I'm wondering if I got the right ones. Here's what stamped on the five taps:

M5x0.8
M4x0.7
M3x0.5
M2.5x0.45
M2x0.4

Are these the "standard" metric threads we commonly use in helis? I ask because I tried to run the M3 tap into a known M3 fastener and it wouldn't go without creating metal shavings. Obviously I don't want to ruin my parts by using the wrong tap. Thanks in advance!

- Jon

Jerry wins!

01-12-2008 03:10 AM

cdrking
Elite Veteran
Location: Seattle

I know for sure the 3 mm is correct and it appears that all the others are correct for our use.

I've noticed the same thing with the shavings. I use a die and run bolts through it to remove old loctite. I've tried to use the tap in some things, it seems to depend on how well it was made as far getting some shavings with it.

Jeff

To hover is divine, the alternative is rather PLANE.

01-12-2008 03:18 AM

kglassman
Heliman
Location: phoenix arizona USA

Hi Jon, The correct die is 3.05 for the 3mm screws and I also use the die when cleaning up the threads on my cap screws. This is the best way to get off all the locktite on the threads. I also keep a tap in a tap handle to clean up threaded fittings. Hope this helps you.

01-12-2008 04:00 AM

jrvander
Senior Heliman
Location: Mystic, CT

Thanks for the info guys, helps alot. I tapped a couple of jobs last night with the M3x0.5 tap and it worked, however I wouldn't reccomend buying Dubro brand taps to anyone - soft steel. I was tapping aluminum about 3/16" thick and I could see the tap flexing/twisting as I turned it. They're probably low quality Chinese tools from the same source as Harborfreight Tools stuff.

Jerry wins!

01-13-2008 03:42 PM

kglassman
Heliman
Location: phoenix arizona USA

Jon...I found using some wax on the threads of the tap and turning only 1/4 turn then backing off then doing it again till you have what you are threading saves on the tool and keeps the tap from loading up. works for me.

01-13-2008 10:12 PM

Peefor
Veteran
Location: St Albans UK

A few drops of paraffin/kerosene is good for tapping aluminium. Would tend to agree - Dubro stuff seems to be made of metal with plastic tendencies.

Pete

01-13-2008 10:42 PM

kglassman
Heliman
Location: phoenix arizona USA

Peefor...why I said wax is because it traps the shavings and is useful when taping a blind hole and as it loads up you clean off the tap and reply the wax. I use cutting oil when taping flat stock aluminum or steel.

01-14-2008 12:23 AM

hootowl
Elite Veteran
Location: Garnet Valley, Pa.

Little tip..

Obviously the drilled hole needs to be smaller than the tapped hole.

This only works with metric but is right on.

Take the tap size and subtract the pitch. This will be the drill size.

3mm x .5 use a 2.5mm or equivalent drill.

Give man fish and he will eat for a day. Teach man how to fish, he will sit in a boat &drink beer

01-14-2008 12:57 AM

HOMEPAGE

jrvander
Senior Heliman
Location: Mystic, CT

Thanks for the tips, guys. The hole was drilled through(not blind) so I figured the shavings would fall through, which most of them did. The hole was drilled using the matched bit supplied by Dubro, can't recall exactly what size it was right now.

I have a set of nice quality tap&dies in standard size that I use for various jobs, they don't twist like this one did. I was really leary that the tap would snap in two by the twist it was showing. I finished the job at hand, but I'll be buying better taps soon.

- Jon

Jerry wins!

01-14-2008 02:16 AM

1 page

303 views

POST REPLY

MRC/Altech Marketing USA	.	JR-Spektrum	.	E-flite
	.		.

Tools and Field Equipment > Thread pitch for M3 metric screws

UPDATE SCREEN PRINT TOPIC

Advertisers

Subscribe to This Topic