Thermally Cut Bolt Hole Roughness and Procedure

Date 12-06-2012 12:16

I had to compare the old 2004 RCSC against the new 2009 RCSC and noticed a change that now allows "thermally cut holes produced my mechanical means are permitted in statically loaded joints" automatically; previously they had to be approved by the EOR(3.3).

My question is with the roughness requirements of the holes and the 1000 uin (microinches).

I have the plastic sample C4.1-77 Surface Roughness Guide for Oxygen Cutting. But I don't have any paperwork with it. From looking back in the 2008 D1.1 sample #3 I believe is 1000uin, and sample #4 is 2000 uin.

Could someone please confirm this for me and also tell me what are sample #1 and 2?
The decal on the back doesn't tell me what each sample is, it only describes the definitions of flatnes, angularity, draglines, ect.

Thanks

By welderbrent (*****)

Date 12-06-2012 14:41 Edited 12-06-2012 14:47

Good morning Chris,

According to my records you are looking at it backwards. If you look at D1.8-2009, Clause 6.10.2.1 & 6.11.3 then sample #4 is equivalent to 500 uin. Then, looking at D1.1-2008, Clause 5.15.4.3 sample #3 is 1000 uin and #2 is 2000 uin. So, I would speculate that #1 is about 3000 uin.

The paperwork that comes with the samples of C4.1-77 (which I have right here in front of me) does not explain/state the relationship between sample # and uin.

Have a Great Day, Brent

By eekpod

Date 12-10-2012 18:15

welderbrent,
sorry for the delay, I needed time to sit back down and go over this.
I don't have D1.8 to referance.

But I do agree with you that sample #3 is 1000uin which covers up to 4" thick.
Sample #2 is 2000 uin which covers 4"-8". I got all that from 2008 D1.1.

I agree and think sample #1 would be a higher number, and could be 3000uin, by following the pattern. Not sure not going to speculate unless I see it in writing.
Thanks for the help. You'd think they would just label it to match and make an easy referance.

Chris

By welderbrent (*****)

Date 12-10-2012 18:21

I always have to stop and regroup when looking at these units. My mind goes to sanding grits which are finer as they get larger.

But, here we get a finer surface finish as the numbers get smaller. Backwards to me with all the fabricating work I have done for years.

I need to look it up and see 'why' their numbers go that direction and what they represent.

Have a Great Day, Brent