Helicoil help. With photos.

manchester1

manchester1

#1
#1
I have a 5/16 course thread hole that is kinda stripped. It is the neck for the Holder mini bike. I don't want to tap to 3/8 as the little neck is not that thick. My question is can I use a helicoil in this spot? Can I use a 5/16 helicoil in the semi stripped hole? Thank you.
 
M

Moderator

Administrator
#11
#11
manchester1 said:
I have a 5/16 course thread hole that is kinda stripped. It is the neck for the Holder mini bike. I don't want to tap to 3/8 as the little neck is not that thick. My question is can I use a helicoil in this spot? Can I use a 5/16 helicoil in the semi stripped hole? Thank you.
Click to expand...
The major diameter of the 5/16-18 Heli-coil tap (.388) would be larger than a 3/8 tap.

I think kayde has the right idea, drill and tap it deeper and use a longer bolt.
 
Addicted 2 Minis

Addicted 2 Minis

Well-Known Member
#13
#13
It's hard to tell but that looks like a pretty shallow hole for the job it has to do. I wonder if the bottom of the hole is really the top of the old bolt that may have broke off previously. Although the handlebar bracket is keyed and there's no side to side force on the bolt, it still has to hold it down firmly. One would think an 1"-1-1/2" deep would be adequate. I would find a drill bit that fits snug inside the threaded portion and drill just enough to get a center started then switch to a smaller bit for the 5/16" tap and make it at least 1" deep. If all else fails, your welding buddy can fill the hole with weld and you can re-drill it but your nice chrome will turn blue.
 
manchester1

manchester1

#16
#16
Well, I think just tapping the hole a little deeper will do the trick and a great idea that was suggested. Only problem now is my tap is only a inch long. lol. I was able to make a couple new threads to at least stop the bars from falling off. lol. I will need to buy or borrow a longer tap.
 
massacre

massacre

#17
#17
They make “tap sockets”, which have a square that fits the square end of the tap.
Maybe that could help you, using an extension to get down deeper?


Or maybe the socket is too big?
 
FOMOGO

FOMOGO

#18
#18
manchester1 said:
Well, I think just tapping the hole a little deeper will do the trick and a great idea that was suggested. Only problem now is my tap is only a inch long. lol. I was able to make a couple new threads to at least stop the bars from falling off. lol. I will need to buy or borrow a longer tap.
Click to expand...

Your probably going to need a bottoming tap to thread all the way to the bottom of the hole. A standard tap set usually only has starter taps. They are fine in a through hole but not in a blind hole.

Here is a set of 3 taps

Standard High Speed Steel Hand Tap Sets | 425774 | Travers Tool Co., Inc.

Tap sockets

Amazon.com: Lisle 70500 Tap Socket Set: Automotive
 
FOMOGO

FOMOGO

#20
#20
manchester1 said:
Thank you.
Click to expand...
Measure the depth of the hole in the neck and mark the tap at that depth. You don't want to bottom out the tap and run the risk of breaking it. But you do want to go as close to the bottom as you can. Better to have a taped hole 1 1/4'' deep while using a 1'' bolt. You don't want to bottom the bolt out in the hole either. Use good taping fluid. NOT WD40.... Most folks like Rapid Tap. Its good for drilling too. Once you try it you will use it forever.

Remember not over 1 full turn in and 1/2 a turn out to break the chip. Always 1/2 turn out. You will feel the chip break.

Rapid Tap Cutting Fluid | 31051 | Travers Tool Co., Inc.
 
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