Calculation of Bolt Length Based on ASME B16.5

[qiuniu]

I have 2 very fundamental questions about the calculation of bolt length based on ASME B16.5
1. For the specified bolt lenth, it is said that"which is calculated bolt lenth rounded off to the nearest 5-mm increment".
Is this means that if the calculated length is 46.1, it will be rounded to 45, and 48.0 will be rounded to 50.
2. The negative tolerance is a positive valve acutally, right?

Thanks a lot.

 

[gr2vessels]

Question 1.
If your calculated bolt length is 46.1 mm, the nearest incremental rounding will be 50 mm. Ditto, if your calculated length is 48 mm, then the incremental rounding is also 50 mm. Accordingly, if there is a calculated length of 49.6 mm, the next rounded length is 50 mm.
Question 2.
Run a spelling check before posting the question. As for the question, there is no negative tolerance to the incremental rounding, you always round up, not down. Otherwise, you'll end up with a shorter bolt than the minimum calculated length.
Cheers,
gr2vessels

 

[qiuniu]

Thank you very much for your reply.