Jump to content


Photo

Zinc plating suspension bolts


  • Please log in to reply
20 replies to this topic

#1 tuxedoss

tuxedoss

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,023 posts
  • Name:Brett
  • Location:Sydney
  • Car:ss
  • Joined: 29-July 11

Posted 02 April 2019 - 03:25 PM

Was looking at getting all the K frame and rear training arm bolts and nuts zinc plated. Then saw the plating process can make them brittle due to hydrogen embrittlement. Anyone done this and had any issues ? From what I read the harder the bolt the worse it is so is it only an issue for high tensile bolts , the k frame bolts look to be just normal bolts ,the only marking on them is a star so no rating by the looks

#2 torana?

torana?

    Forum Member

  • Members
  • PipPipPip
  • 94 posts
  • Location:QLD
  • Joined: 23-May 06

Posted 02 April 2019 - 05:58 PM

The star is the rating the more points the stronger the bolt

#3 tuxedoss

tuxedoss

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,023 posts
  • Name:Brett
  • Location:Sydney
  • Car:ss
  • Joined: 29-July 11

Posted 02 April 2019 - 06:43 PM

The star pattern is different to what google shows but the control arm bolts and rear trailing arm bolts have 6 points making them grade 8 but the UNF caliber bolts which look to be hi tensile only have 3 points .

#4 grumpy xu1

grumpy xu1

    Lotsa Posts!

  • Members
  • PipPipPipPipPipPip
  • 2,809 posts
  • Name:Gary
  • Location:Queensland
  • Car:lj xu1
  • Joined: 01-February 10

Posted 02 April 2019 - 06:46 PM

Tell your plater, they're suspension bolts, he may change the prep process a little for that reason, if they're cone nuts, don't forget, they're single use, in reality.

#5 tuxedoss

tuxedoss

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,023 posts
  • Name:Brett
  • Location:Sydney
  • Car:ss
  • Joined: 29-July 11

Posted 02 April 2019 - 07:16 PM

Tell your plater, they're suspension bolts, he may change the prep process a little for that reason, if they're cone nuts, don't forget, they're single use, in reality.

I did and thats how the conversation started, he said they need to be baked within 24 hours of plating but he can't do it and only place he knew only does big batches and is expensive.

While the pattern on the bolt is not quite the same as I've found with google I'd say its a grade 8 bolt, surprised the caliper bolt is only grade 5

 

Attached File  bolt.jpg   22.65K   5 downloads

 

Attached Files



#6 V-SLR5000-P

V-SLR5000-P

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,300 posts
  • Location:Victoria
  • Car:L34 x 2
  • Joined: 14-November 06
Garage View Garage

Posted 02 April 2019 - 07:40 PM

Three to four hours in your home oven at 375 degrees F should see the hydrogen removed. The higher the tensile strength of a bolt the longer the baking time required. Baking must be done within an hour of plating.



#7 WhiteA9XS

WhiteA9XS

    .

  • Members
  • PipPipPipPipPip
  • 1,646 posts
  • Name:Shaun
  • Location:Billys Creek
  • Car:LJ LX
  • Joined: 08-November 05
Garage View Garage

Posted 02 April 2019 - 08:01 PM


Been zinc plating bolts for years including suspension bolts , never had one break yet , I try and use the original old bolts if in good condition if possible .

I have heard from an engineer that the old grade 8 bolts are stronger than the new grade 8 bolts .

#8 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,461 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 02 April 2019 - 09:42 PM

My plater is a baker

But he's in Perth

Find a better plater... one that does aircraft stuff



#9 Ice

Ice

    Cool

  • Members
  • PipPipPipPipPipPipPip
  • 15,102 posts
  • Name:Gene
  • Location:Galaxy's away from Ipswich
  • Car:77 HZ Sandman Van
  • Joined: 03-January 07

Posted 02 April 2019 - 11:14 PM

My plater is a baker
But he's in Perth
Find a better plater... one that does aircraft stuff

Anthony

#10 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,461 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 03 April 2019 - 12:33 AM

Yep thats him

Moved to Maddington now though



#11 Ice

Ice

    Cool

  • Members
  • PipPipPipPipPipPipPip
  • 15,102 posts
  • Name:Gene
  • Location:Galaxy's away from Ipswich
  • Car:77 HZ Sandman Van
  • Joined: 03-January 07

Posted 03 April 2019 - 07:03 AM

Yep thats him
Moved to Maddington now though

Good to know cheers Neil

#12 tuxedoss

tuxedoss

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,023 posts
  • Name:Brett
  • Location:Sydney
  • Car:ss
  • Joined: 29-July 11

Posted 03 April 2019 - 09:37 PM

Thanks for all the info, I have found another plater in Sydney that does baking so will give them a call and see what they say, just not sure if they do small jobs



#13 Ando

Ando

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 519 posts
  • Location:Coolangatta
  • Car:6/'76 L32 SS white & black. 9/'76 L31 SS gold. 5/'77 L31 SS Chamois. 3/'79 UC SL Deluxe hatch.
  • Joined: 10-February 08
Garage View Garage

Posted 04 April 2019 - 05:02 AM

Do a home destructive test on one that's been zinc plated. Use a press to test shear. A hammer to test impact.

 

I'm a bit sceptical that an electrolysis process can change the metallurgical structure of a high tensile bolt, rendering it brittle. 

 

Heating & quenching..Yes but that's another matter.  

 

Would be interesting to see the results.



#14 S pack

S pack

    Scrivet Counter

  • Members
  • PipPipPipPipPipPipPip
  • 15,522 posts
  • Name:Dave
  • Location:Luggage Point
  • Car:73 LJ
  • Joined: 25-January 10

Posted 04 April 2019 - 06:43 AM

Some light reading https://www.greensla... Appearance.pdf



#15 Ando

Ando

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 519 posts
  • Location:Coolangatta
  • Car:6/'76 L32 SS white & black. 9/'76 L31 SS gold. 5/'77 L31 SS Chamois. 3/'79 UC SL Deluxe hatch.
  • Joined: 10-February 08
Garage View Garage

Posted 04 April 2019 - 09:51 AM

A good read. My conclusion from that is;

 

The Torana suspension arm bolt is a grade 8 type (Rockwell C36) & it isn't used in a high tensile application. 

 

A destructive test would be in order, for ones peace of mind though.. 



#16 tuxedoss

tuxedoss

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,023 posts
  • Name:Brett
  • Location:Sydney
  • Car:ss
  • Joined: 29-July 11

Posted 04 April 2019 - 04:27 PM

I reckon youd be unlucky for a failure but just wasn’t sure , seems a grade 8 can be 33 to 39

#17 Toranamat69

Toranamat69

    Forum R&D Officer

  • Members
  • PipPipPipPipPip
  • 2,117 posts
  • Location:Brisbane
  • Joined: 07-November 05

Posted 04 April 2019 - 04:43 PM

At work we had a recent failure of a zinc plate high tensile bolt inside a gearbox of a train gearbox. Metallurgical analysis concluded this was hydrogen embittlement. It can happen but that is the first time ive physically seen it happen. Bolt was not in a high stress application. Highest stress was from initial tightening torque.

#18 grumpy xu1

grumpy xu1

    Lotsa Posts!

  • Members
  • PipPipPipPipPipPip
  • 2,809 posts
  • Name:Gary
  • Location:Queensland
  • Car:lj xu1
  • Joined: 01-February 10

Posted 04 April 2019 - 07:06 PM

I believe it's mainly the pickling process & brightner that can cause any issue. So i would be changing the prep procedure a little.

#19 WhiteA9XS

WhiteA9XS

    .

  • Members
  • PipPipPipPipPip
  • 1,646 posts
  • Name:Shaun
  • Location:Billys Creek
  • Car:LJ LX
  • Joined: 08-November 05
Garage View Garage

Posted 04 April 2019 - 08:05 PM


Thanks for the link Dave , just as well I didn’t toss the old oven , moral of the story don’t clean bolts with acid , I use bead blasting wash with water then dip .

#20 tuxedoss

tuxedoss

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,023 posts
  • Name:Brett
  • Location:Sydney
  • Car:ss
  • Joined: 29-July 11

Posted 04 April 2019 - 09:48 PM

Thanks for the link Dave , just as well I didn’t toss the old oven , moral of the story don’t clean bolts with acid , I use bead blasting wash with water then dip .

Yes it seems the issue is more with the acid cleaning than the plating



#21 grumpy xu1

grumpy xu1

    Lotsa Posts!

  • Members
  • PipPipPipPipPipPip
  • 2,809 posts
  • Name:Gary
  • Location:Queensland
  • Car:lj xu1
  • Joined: 01-February 10

Posted 05 April 2019 - 06:09 PM

Yes it seems the issue is more with the acid cleaning than the plating


That's what the pickling process is.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users