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Up Topic Welding Industry / Technical Discussions / Tack Welding Grade 5 Bolt Heads / Nuts
- - By James Casper Date 11-18-2009 19:41
Is it acceptable to tack weld a Grade 5 bolt head / nut in place? The weld creates a brittle martensitic area as well as removes the manufactuers heat quech in that area, but how large is the heat effected area? 
Parent - - By 3.2 Inspector (***) Date 11-18-2009 19:53
[deleted]
Parent - By G.S.Crisi (****) Date 11-18-2009 19:57
Why are you so sure that jrw159 doesn't know?
Giovanni S. Crisi
Parent - By jrw159 (*****) Date 11-18-2009 21:52
I know just a little about grade 5 nuts, not much. AISI 1008 - 1026 steel that conforms to the following:
Carbon: .55% maximum, Manganese: .30% minimum, Sulfur:.15% maximum. Rockwell C32 maximum.

I also know there is another type of grade 5 nut. It is YOU! Someone that acts like a nut who is barely in grade 5.

STOP BRINGING DOWN OTHER PEOPLES THREADS WITH YOUR CHILDISH BS!!!!

jrw159
Parent - - By waccobird (****) Date 11-18-2009 20:24
James Casper
Well surely don't ask 3.2 as he if it is a he is an instigator LoL.
Not really enough info anyway.
But the best answer can be gotten from the Customer's Engineer of Record.
Good Luck
Marshall
Parent - - By 3.2 Inspector (***) Date 11-18-2009 20:31
[deleted]
Parent - - By waccobird (****) Date 11-18-2009 20:48
3.2 Inspector
yes I do know that the size of the HAZ is directly related to the heat input.
But I don't know anything about the hardness being directly related to delta 8/5.
Is it Zinc Coated, Plated, or plain LoL
But I do feel you enjoy yanking chains more than most and I wish you would give the forum your best information instead of your stirring agitation.
Take Care
Marshall
Parent - - By 522029 (***) Date 11-19-2009 00:19
Yanking one's chain is all 3.? can accomplish.

Do your best to just ignore ____.

Griff
Parent - By 3.2 Inspector (***) Date 11-19-2009 11:23
Yes, no more, no less.

3.2
Parent - By G.S.Crisi (****) Date 11-18-2009 21:53
James,
if you're afraid to tackweld the bolt head and nut in place and want to be sure they won't loosen down, you can use a lockwasher. That's why lockwashers were invented.
Giovanni S. Crisi
Sao Paulo - Brazil
Parent - - By 522029 (***) Date 11-19-2009 00:21
Being a grade 5, the strength is not likely to be that critical.  If strength is indeed critical, use a grade 8.

Griff
Parent - - By Paladin (***) Date 11-19-2009 04:07 Edited 11-19-2009 14:26
Would tacking a small piece of steel up against(not to) the head of the nut or bolt work in this situation? That would keep it from turning and not affect the strength of the bolt or nut. On certain large trenchers a "wrench" is cut out of mild steel and bolted or tacked to the frame to keep an important bolt from backing out in high vibration conditions.
Parent - By jwright650 (*****) Date 11-19-2009 15:40
^^This would have been my suggestion as well.....this has worked for us in the past when tack welding the fastener was completely out of the question. Capture the nut in a plate assembly or weld a plate against the side of the flats of the bolt head itself. There are a couple of ways to accomplish this.
Parent - - By RonG (****) Date 11-19-2009 17:52
James Casper # 1  Are these bolts tourqed to max speck? Are they on the front end of an Automobile? If so welding is not adviseabled

what size of bolt (nut) are we talking about and what welding process? Unless you are concerned the head of the bolt may break off and go thru a machine what harm is a small hardened area.

If the bolt is large enough and weld process quick enough that may be the extent of harm. I doubt it greatly effect the strength but may may crack but then it would still serve as an Anti-rotation devise.
Parent - By Superflux (****) Date 11-19-2009 21:33
Under "the best weld is no weld" philosophy, could a drilled bolt with lock wire or Cotter pin and Castle nut be an option?
There are those applications in certain pieces of machinery I've worked on where blocks are tacked ot bolt heads and nuts as a "tattle tale" to loosening fasteners. It is in my opinion an Archaic method and should be avoided.
Another option would be to Stake the threads or mushroom the end of the bolt for retention.
Parent - By waccobird (****) Date 11-20-2009 11:00
James Casper
I hope you solved you dilemma.
I have had nuts called to be welded/tacked to parts before.
They were 7/8" A325 tho and they were detailed and had been approved by the Engineer of Record.
They allowed  for the splice connection of a 200' Pedestrian Walkway and the customer was the FDOT. It did require a procedure.
I believe you got some good input from the forum for the info you gave.
Good Luck
Marshall
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Up Topic Welding Industry / Technical Discussions / Tack Welding Grade 5 Bolt Heads / Nuts

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