ASME B16.5 2013 3

[jose0908]

Is there some kind of tolerance on diameter of bolt hole. Example on a 4" 150# Flange the dimension given is .750 What would be the +- tolerance. If there is a tolerance, would it be different depending on the size?

 

[HTNeighbors]

This is not from the 2013, but the 2009 edition...

7.8.1 Bolt Circle Diameter. The required tolerance for all bolt circle diameters is as follows: ±1.5 mm (±0.06 in.)

 

[XL83NL]

HTNeighbors, your specified tolerance is on bolt circle dia, the OP asks for bolt hole dia.
I think the answer is in B16.5:2013 para 7.8.2:

7.8.2 Bolt Hole to Bolt Hole. The required tolerance
for the center-to-center of adjacent bolt holes is as
follows:
±0.8 mm (±0.03 in.)

Hope this helps.

 

[HTNeighbors]

In re-reading the original question, I think the answer best answer would be in Table 11-7 and the following, similar tables. These tables list the diameter of the bolt hole and the diameter of the bolts. There is no tolerance given; it merely lists a bolt of 1/8" diameter smaller than the hole diameter.

In answer to the original question - I'm not aware of any tolerance acceptance for diameter of bolt holes.

 

[jose0908]

Thank you guys for your help.
XL8NL Doing the measerement for adjacent bolt holes would be a task to get an accurate measurement using dial calipers, but yes that would be the tolrerance.

HTNeighborsI see your point where B16.5 Table 11-7 points out diameter of bolts.

Considering the diameter of bolts given, would flange be rejectable if diameter of bolt hole is smaller than diameter of bolt?

Again thank you guys

 

[HTNeighbors]

Yes - if the diameter of the bolt hole is smaller than the diameter of the bolt - the bolt will not fit in the hole - this would be a reject. Not manufactured to spec.

 

[Engdoitbetter]

Hi all,

I give my two cents to the discussion.
I noticed this detail years ago, my opinion is that hole position (bolte circle + hole-to-hole) is important since it is the basis for a good flange alignment, while bolt diameter has only to be large enough to accommodate the bolt with sufficient clearance, as the bolt is expected to carry only axial load. IMHO this is why there is no tolerance on bolt diameter.

Further suggestions?

Stefano