| Get answers to your structural bolting questions here.
Cooper and Turner are widely acknowledged as one of the UK's leading authorities on structural bolting and as such are uniquely placed to answer your queries.
This page attempts to provide straight forward information that will answer some of the most frequently encountered questions.
Use the drop down box to select a subject heading
If, after searching these pages, you still have a question, submit your enquiry >>HERE<<
Disclaimer / Product Liability
Whilst this website and the information it contains are provided in good faith, no member of the Andaray group of companies shall be under any liability in respect of the contents of this website or for any reliance the user may place on it.
|
|
Calculation of HSFG bolt lengths
Q: How do I calculate the correct length for BS 4395 Part 1 and Part 2 HSFG bolts?
To calculate the correct length for BS 4395 Part 1 and Part 2 HSFG bolts the grip length, i.e. the total thickness of the members to be bolted together, should be added to the length shown in the table below. The figure allows for the thickness of one flat round washer, the nut and sufficient bolt protrusion through the nut
|
Norminal Diameter
|
Addition to Grip length to give length of Bolt required #(mm)
|
|
M12
|
22
|
|
M16
|
26
|
|
M20
|
30
|
|
M22
|
34
|
|
M24
|
36
|
|
M27
|
39
|
|
M30
|
42
|
|
M36
|
48
|
# An additional 3mm should be added to these allowances if ‘Coronet’ Direct Tension Indicators also known as Load Indicator Washers are used. If taper washers are used an additional allowance equal to the thickness of the taper washer should be made. If the length obtained is between bolt lengths, the total length is rounded off to the next longer.
|
