OT: Bolt Identification Question (Drill Ship Related)

[RingSteel]

I'm trying to determine the bolt grade of some existing bolts, to order replacements. The bolts don't have the usual ASTM markings on the head, and I've searched my manuals and came up blank.

The bolts are used on a Dreco derrick as foundation bolts for the deadline anchor. I guess that makes them pretty important.... .
The description of the bolts is:

"These are size 2-1/2” -8 (threads/inch). As I described yesterday the head of the bolts are slick, they do not have the raised service type hash marks that we normal see on bolts indicating grade. But there is a stamp which has six small hash marks, in a circle with the letter H in the middle."

Does anyone have any ideas?

[Bill]

I can't help. Call these guys out here. They are the top place in the silicon valley for anything that is threaded. They may want you to take a picture and email it to them.

Olander Co Inc

https://www.olander.com

144 Commercial Street
Sunnyvale, CA 94086-5298
(408) 735-1850

[Stins]

First off, I would say that you need to consult the appropriate engineers becasue you need to ensure that you get the right material for strength and corrosion purposes.

Also, the markings you described dont ring a bell to me, the letter "H" could be an indication of 2H material but that is more commonly used for the nut.

I would suggest looking into using a B7 or a grade 660 bolt, both 105ksi yield and should be suitable for critical structural bolting in a marine environment. However like I stated before, consult the structural engineer.

[Atfulldraw]

Call the folks over at Quality Screw and Nut in McAllen. 956-630-1501

Or Quality Bolt and Screw in Ascension Parish, LA (225) 744-1100

[KHo]

Just spoke with our bolt / stud "dude"...he said the six hash marks more than likely denote SAE Grade 8 and the "H" would denote the manufacturer...whoever that is. As Travis mentioned, get with engineer to insure you are getting the right creature.

[RingSteel]

Thanks for the help! So far the consensus is that the bolts are "likely" Grade 8, but everyone is suggesting getting confirmation from the manufacturer before replacing the bolts.

For right now, I'll have to wait on pics of the bolt heads from the rig and wait for the manufacturer to return a phone call.

I appreciate the help!

[STICKIT]

sounds like a grade 8.

[Bill M]

Just spoke with our bolt / stud "dude"...he said the six hash marks more than likely denote SAE Grade 8 and the "H" would denote the manufacturer...whoever that is. As Travis mentioned, get with engineer to insure you are getting the right creature.

This. Used to run a fastener Quality dept in my previous career. You might try googling the H as it has to be the manufacturer as Kevin mentioned. He gave you the grade also.

[Matthew]

SIX marks is Grade 8 SAE-J429 also ASTM-A354 Grade BD. The H is prolly the manufacurers mark.

[Chuey]

take apicture of it

[Bullrdr82]

I'm trying to determine the bolt grade of some existing bolts, to order replacements. The bolts don't have the usual ASTM markings on the head, and I've searched my manuals and came up blank.

The bolts are used on a Dreco derrick as foundation bolts for the deadline anchor. I guess that makes them pretty important.... .
The description of the bolts is:

"These are size 2-1/2” -8 (threads/inch). As I described yesterday the head of the bolts are slick, they do not have the raised service type hash marks that we normal see on bolts indicating grade. But there is a stamp which has six small hash marks, in a circle with the letter H in the middle."

Does anyone have any ideas?

SIX marks is Grade 8 SAE-J429 also ASTM-A354 Grade BD. The H is prolly the manufacurers mark.

From the sound of things, I do not think the "hash" marks are what they normally would be, it sounds a lot like a logo.

Matthew - Is it just me or does SAE and ASTM only go up to 1.5" dia. for bolts. thanks for the PDF of that, I always just have to go look it up in the Machinery Handbook.

I know in all of our subsea structures we either use B7 or L7 for that size. I would think the manufacturer should have all the required documentation, and that is who you need to get with. It may take some time, but they should have all the paperwork.

[RingSteel]

Update:
Just got the original design drawings from the Manufacturer, and the specs call for a Gr. 5 bolt. I guess as long as grade 5 is a minimum, then using a grade 8 is all good.

Two things bother me a bit though. First is that if it was installed with grade 5 bolts, when where the bolts changed to the current grade 8 (and who did it without documenting it)? The other part is the field guys called the threads at 8 per inch, and the standard 2 1/2" dia bolt thread is 4.

Got any thoughts about the threads per inch?

I'm waiting for a pic from the rig, but I'm not holding my breath. I know how busy they are, and I know how tall the derrick is. lol I'd be reluctant to hurry out there and climb the derrick just to take a pic too.

[Bullrdr82]

I have always been told anything over 1.00" for NC threads was 8 threads per inch. 4 Threads per inch sounds more like an acme thread.

I could be wrong, but that is what I have always been told.

[1369]

Ring, did your guys say what the thread end of the bolt looks like? Maybe they're some of those speciality tension control bolts along the lines of a Lejuene bolt?