BMWSportTouring

M5 Helicoil - Coarse or Fine and where to get?

Posted By: RedMac

M5 Helicoil - Coarse or Fine and where to get? - 05/25/10 01:19 AM

I just stripped out one of the screw holes on my windshield mount (it doesn't help that I change the windcreen about 10 times a year).

Is the M5 screw a coarse or fine thread? Anyone have a good source for a kit? (I do see Amazon sells them)

Thanks in advance
Posted By: Satguy

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/25/10 01:38 AM

Probably M5 X .8

I dunno.... is there enough "meat" in the windscreen arm to drill out and install a helicoil?

I think I would go up to M6 X 1.0 and just purchase some stainless steel button head cap screws to replace the M5s

Good Luck
Posted By: workin' them angels

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/25/10 03:21 AM

Originally Posted By: RedMac
I just stripped out one of the screw holes on my windshield mount (it doesn't help that I change the windcreen about 10 times a year).

Is the M5 screw a coarse or fine thread? Anyone have a good source for a kit? (I do see Amazon sells them)

Thanks in advance


Looks like a m5x16 SI

parts link
Posted By: NewBlue

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/25/10 11:23 AM

A metric pitch usually changes in quarters. I would guess it's .75 or 1.0mm. Take your bolt to an auto parts store or local garage, they can check it with a pitch gauge. The 16 is probibly the length in mm.
You can measure the length, rotate one revolution, re-measure the length, subtract it from the first reading and get the pitch but that's way to much work.
Posted By: Anton Largiader

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/25/10 11:35 AM

M5x0.8 if it's a standard BMW fairing bolt.

If you are constantly changing that windshield, the helicoil is a good idea anyway.
Posted By: Selden

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/25/10 12:32 PM

Originally Posted By: Satguy
Probably M5 X .8

I dunno.... is there enough "meat" in the windscreen arm to drill out and install a helicoil?

I think I would go up to M6 X 1.0 and just purchase some stainless steel button head cap screws to replace the M5s

Good Luck

Given tales of snapping arms, this was the first thing that I wondered about when reading the question. Assuming there is clearance on the bottom of the support arm, I would be inclined to use a longer screw, with a nut behind. OR, replace the arm.
Posted By: RedMac

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/25/10 08:03 PM

Thanks for all the responses... It is a standard fairing bolt. The kits I've seen either say "coarse thread" or "fine thread". According to this chart an M5 x .8 would be a coarse thread.

http://www.engineershandbook.com/Tables/metrictapdrill.htm

Thanks

I think the arms snapping are the windshield arm support arms (I've already replaced mine with aftermarket ones.)

I'm probably going to replace them all with Helicoils since it is just tapped aluminum.
Posted By: NewBlue

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/26/10 12:47 AM

I learned something new today and that's always a good thing. Some really fine thread pitch when you drop to M5 and below. Anyway I pulled a shield screw and it is in fact 5 X .8 The chart I have shows a common pitch for the M5 as either .9 or .8 a call before ordering to get the exact pitch of the helicoil kit could save some time.

Good Luck on the repair.
Posted By: Anton Largiader

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/26/10 01:12 PM

Their use of 'coarse thread' is a bit confusing. I think of it more as standard thread vs fine thread(s). As you can see there are sometimes more than two pitches for a given diameter.
Posted By: Dick_at_Lake_Tahoe_NV

Re: M5 Helicoil - Coarse or Fine and where to get? - 05/26/10 05:13 PM

Go to your local Napa store. They have a complete kit for about 25-bucks that has the drill, Insertion tool and 8-helicoils.
Posted By: RedMac

Re: M5 Helicoil - Coarse or Fine and where to get? - 06/03/10 12:41 AM

No joy at my local Napa store. Said he'd have to order it... I'll try one over in the next town before I try off the Internet.
Posted By: Bswag

Re: M5 Helicoil - Coarse or Fine and where to get? - 06/03/10 02:32 AM

I had the same problem, and what I did was put a m5X20 it worked fine.
Posted By: RedMac

Re: M5 Helicoil - Coarse or Fine and where to get? - 06/03/10 04:06 PM

After calling every auto parts store within a 20 mile radius, found one at the NAPA store down in Antioch. I should have asked the price first. Drove 20 miles down there. Kit was $42.00!!! and no drill bit.

Already invested the gas and time, so I just bought it. Had to also trip over to the hardware store to buy the bit (it was probably the ONLY bit I don't already own).

Whole process went fine and I'm back in business.
Posted By: workin' them angels

Re: M5 Helicoil - Coarse or Fine and where to get? - 06/03/10 04:36 PM

clap

Glad to hear it went back together smoothly! Here's to having that behind you and great riding days ahead!
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