Outer thread size on helicoil

[Subieguy165]

Have a oem fix-a-thread helicoil set and I don't know what the outer diameter is for a tap can someone help me out?

Part number - 25648

[golucky66]

What size if the helicoil for? Like a 8mm x 1.25, 6mm x 1.25.

[Mike104]

M14 x 1.25

 

14.30MM drill

 

https://www.thorintl.com/Drill-Sizes-HeliCoils-Metric.shtml

 

Google is your friend!

 

About a 9/16 drill bit

Edited August 25, 2017 by Mike104

[Subieguy165]

Well the m14-1.25 is the inner size just can't figure out what is the outside so I can tap the head correctly

[Mike104]

Check my post above.  It needs a 14.30 mm hole size.  There are special helicoil taps to thread them into.

 

Description M14 x 1.25 HSS STI Plug Tap

Product Specs:

• For use with: Helical Screw Thread Inserts
• Use with Internal Thread Size: M14 x 1.25
• Material: HSS (High Speed Steel)
• Compatible with: Helicoil, Recoil, Perma-Coil, Powercoil or any other standard Helical Screw Thread Inserts

Our Screw Thread Insert (STI) Taps are used specifically to create threads for Helical Thread Inserts.  STI Taps are oversized so the thread produced will accept a Helical Wire Insert of the same nominal size and pitch - meaning the hole created by the Tap goes back to the original dimension allowing the original fastener to be used.

The "Plug" style Tap is ideal for starting or tapping a through hole.  The Tap can be used and the Helical Insert can be installed in most materials including aluminum, magnesium, cast iron, carbon steel, stainless steel, and plastic.  Proudly made in the USA.

 

You need an M14 x 1.25 Screw Thread Insert Tap

 

 

https://www.amazon.com/Metric-Right-Thread-1-25mm-Pitch/dp/B00N1HULOO

Edited August 27, 2017 by Mike104

[Gloyale]

Well the m14-1.25 is the inner size just can't figure out what is the outside so I can tap the head correctly

 

it won't be a standard tap.

 

you need one designed to be used with that size helicoil.  Ussually they are included in the helicoil kit for each given size.

[Gloyale]

Well the m14-1.25 is the inner size just can't figure out what is the outside so I can tap the head correctly

 

m14?  on the head?  what the hell part are you trying to tap?

 

I can't htink of anywhere on a subaru head that uses m14?  unless you are meaning the spark plug hole.

 

If that's the case DO NOT use a helicoil or other helical insert.  You need a full sleeve "spark plug hole" repair kit.

 

might be better off trying to find a good core head to use rather than trying to fix.  It can be tricky on those deep recessed holes and if you screw up you will have spark plug rocket out of the hole.

[Subieguy165]

Fixed sparkplug hole finally

[dumpstar]

These inserts have an: Outter diameter: M17 x 1.25 pitch

Inner diameter: M14 x 1.25 pitch

 

If you get the OEM M14 1.25 Fix-A-Thred kit, that tap is the correct size to tap the spark plug hole-- but it absolutely will not fit down into the spark plug hole with a socket around the head of the tap (it's simply too fat). I had a smaller diameter deep socket welded to the top of the head of the tap at a local machine shop for $20. Then i was able to use the welded on deep socket's drive hole, a ratchet, and an extension to turn the tap.