bolt will not thread into hole ran a tap through several times - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Garage - Tools
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 12-02-2009, 06:43 PM
Registered User
 
Join Date: Dec 2009
Location: usa
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
bolt will not thread into hole ran a tap through several times

I have a couple head bolt holes that will not accept bolts

I can tap them easily with a taper tap or bottom tap with ease

when I tried to run a head bolt on it would not thread

i went 2 the store and got another new bolt and tried that today. It would not thread on.

Then I tried a chaser bolt but that would not thread on either

Does anyone have any ideas on how to get a bolt to thread on if it does not thread? It seemed to thread on the first try but it jumped off the threads

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-02-2009, 08:53 PM
Registered User
 
Join Date: Nov 2005
Location: Duffield ,Va
Age: 67
Posts: 526
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
what are you working on? Standard or metric? A little more info might help.


Quote:
Originally Posted by hotbrat
I have a couple head bolt holes that will not accept bolts

I can tap them easily with a taper tap or bottom tap with ease

when I tried to run a head bolt on it would not thread

i went 2 the store and got another new bolt and tried that today. It would not thread on.

Then I tried a chaser bolt but that would not thread on either

Does anyone have any ideas on how to get a bolt to thread on if it does not thread? It seemed to thread on the first try but it jumped off the threads
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-02-2009, 08:57 PM
Registered User
 
Join Date: Dec 2009
Location: usa
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
metric

size m12 x 1.75 thread
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-02-2009, 09:05 PM
Registered User
 
Join Date: Nov 2005
Location: Duffield ,Va
Age: 67
Posts: 526
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Are the taps a good brand or maybe a cheap set from Harbor Freight?
If its a good brand tap and the bolt has the correct thread I see noway you should be having a problem.


Quote:
Originally Posted by hotbrat
metric

size m12 x 1.75 thread
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-02-2009, 09:33 PM
302 Z28's Avatar  
Last photo:
Join Date: May 2003
Location: North Texas
Posts: 10,839
Wiki Edits: 0

Thanks: 1
Thanked 86 Times in 73 Posts
What are you working on. I know that some English cars had a weird thread on them, it wasn't true metric and it wasn't US.

Vince
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 12-02-2009, 10:41 PM
MARTINSR's Avatar
Brian Martin,Freelance adviser
 
Last photo:
Join Date: Jun 2004
Location: San francisco bay area
Age: 56
Posts: 13,443
Wiki Edits: 0

Thanks: 1,577
Thanked 1,331 Times in 1,153 Posts
Yeah, I think it was called "witworth"?

Brian
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 12-02-2009, 10:44 PM
302 Z28's Avatar  
Last photo:
Join Date: May 2003
Location: North Texas
Posts: 10,839
Wiki Edits: 0

Thanks: 1
Thanked 86 Times in 73 Posts
Quote:
Originally Posted by MARTINSR
Yeah, I think it was called "witworth"?

Brian
That's it, thanks Brian

Vince
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 12-03-2009, 05:24 AM
Registered User
 
Join Date: Dec 2009
Location: usa
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by dgcantrellsr
Are the taps a good brand or maybe a cheap set from Harbor Freight?
If its a good brand tap and the bolt has the correct thread I see noway you should be having a problem.
Tap is high grade tap. not from HF; Tap is a bottoming tap marked JAPAN on it. I got it from a bolt specialty shop
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 12-03-2009, 05:46 AM
Registered User
 

Last journal entry: Bringing home the 401 Nailhead
Last photo:
Join Date: Jul 2006
Location: NE Ohio
Posts: 381
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
First off - take the bolt and lay it along the tap. Do the threads match? If not there is the answer.

Second - you said it tried for a few turns but then popped out. This sounds like it tried to cross thread. Take a sacrificial bolt and taper the end on a grinder. Clean up the threads with a thread file and then try it. If that works you may have to chamfer the very top threads of the hole or bolt.

Third - you say a head bolt. Are you trying to screw the bolt into the bare block? If you are trying with the head and gasket on maybe the holes are not lining up.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 12-03-2009, 09:41 AM
pepi's Avatar
How’s that hopey-changey thing
 
Last wiki edit: Determining top dead center
Last journal entry: Quicky frame dolly
Last photo:
Join Date: Mar 2005
Location: Georgia ... USA
Posts: 1,835
Wiki Edits: 8

Thanks: 0
Thanked 0 Times in 0 Posts
You might try using a nut to get an line on the bolt size and verify that tap is correct... could it be the bolt is to short ...?
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 12-03-2009, 10:14 AM
bobjob's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Location: florence az.
Age: 61
Posts: 295
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
it sounds like you are trying to go thru head,,gasket,, then into block,, like other posts said.... shank of bolt is same size of outer dim. of thread,, tap has a lead in on front,, and shank is smaller than min. size of thread... so it would fit even if you are a little off....
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 12-03-2009, 12:12 PM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,915
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
Quote:
Originally Posted by heyjude076
Clean up the threads with a thread file and then try it.

A much better and easier way to clean up threads from tapering a bolt, of if you have to shorten a bolt by sawing or grinding, is to thread a nut (all the way to the shank) onto the bolt first. Then after grinding the threads, either to taper the bolt or to just taper the first thread or two after sawing it off, remove the nut and it will clean up the threads as it comes off. Doing this is much easier than using a thread file and leaves the threads perfectly aligned and clean so it will start straight every time.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 12-03-2009, 05:49 PM
Registered User
 
Join Date: Dec 2009
Location: usa
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by heyjude076
First off - take the bolt and lay it along the tap. Do the threads match? If not there is the answer.

Second - you said it tried for a few turns but then popped out. This sounds like it tried to cross thread. Take a sacrificial bolt and taper the end on a grinder. Clean up the threads with a thread file and then try it. If that works you may have to chamfer the very top threads of the hole or bolt.

Third - you say a head bolt. Are you trying to screw the bolt into the bare block? If you are trying with the head and gasket on maybe the holes are not lining up.

lined up 3 different bolts with the TAP, they line up perfectly
the tap runs through the threads with ease

I took a bolt and grinded 3 sides making a thread chaser, it does not thread on period.

The other 2 bolts do not thread on. All 3 bolts are the same size and thread pitch.

both the bottoming tap and plug tape or taper tap thread on perfectly

I am going to try again with a tapered bolt according to the last response. I do not think its going to work.

I almost think the first thread is not large enough to allow the bolt to thread in
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 12-03-2009, 06:35 PM
Registered User
 

Last journal entry: Bringing home the 401 Nailhead
Last photo:
Join Date: Jul 2006
Location: NE Ohio
Posts: 381
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by hotbrat
lined up 3 different bolts with the TAP, they line up perfectly
the tap runs through the threads with ease

I took a bolt and grinded 3 sides making a thread chaser, it does not thread on period.

The other 2 bolts do not thread on. All 3 bolts are the same size and thread pitch.

both the bottoming tap and plug tape or taper tap thread on perfectly
Not being a smart ***** but this not make sense. Are you sure the tap and bolts are both M12X1.75? I don't have my book here but it may be possible that the bolts may be M13 or M14 with a 1.75 pitch. I suggest you get a nut that is M12X1.75. Try the bolts first and make sure the nut threads on. If it does then try the tap. It should go through the nut with minimal resistance. A lot of taps may cut a little material. That is why thread chasers are used rather taps when cleaning bolt holes.


Quote:
Originally Posted by hotbrat
I am going to try again with a tapered bolt according to the last response. I do not think its going to work.

I almost think the first thread is not large enough to allow the bolt to thread in
If the above suggestion with the nut verifies that both the bolts and tap are M12X1.75 you may have to chamfer the first few threads of the bolt hole. A lot of times if the surface is flat it is very difficult to catch the first few threads of the hole.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 12-04-2009, 03:48 AM
Registered User
 
Join Date: Dec 2009
Location: usa
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by heyjude076
If the above suggestion with the nut verifies that both the bolts and tap are M12X1.75 you may have to chamfer the first few threads of the bolt hole. A lot of times if the surface is flat it is very difficult to catch the first few threads of the hole.
I was thinking about this today. If I hammer on a tapered bolt would that work to chamfer up the first threads
Reply With Quote Quick reply to this message

Recent Garage - Tools posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tap Hole Sizes? 345 desoto Engine 3 04-12-2009 02:47 PM
"Bowed" deck lid cruzinTLT Body - Exterior 3 03-04-2005 10:24 PM
Door Alignment Ron M Body - Exterior 2 08-21-2004 02:43 AM


All times are GMT -6. The time now is 03:48 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.