BoxBolt vs. Traditional Methods

BoxBolt Cost Comparison vs. Traditional Methods

Typical End plate detail using four BoxBolts M16

The opposite connection is a very common connection for steel hollow sections and it is for this reason we have decided to select it for a comparison between our BoxBolt and traditional methods.  There are almost an unlimited range of additional connection details that can be found on our website or in our full technical.  The site labour rate has been assumed at rates for 2012 and compared with our material costs to the end user for BoxBolt components at the same time.

Drilled, tapped and Bolted Detail (M16 High tensile bolts)

The below table is based on pre-drilling the holes of the secondary steel member off site and drilling holes in the existing structure to match on site.  The bolts will be high tensile grade 8.8 or A470.

Connection Requirements Rate/hr
(£)
Time
(hrs)
Step Cost
(£)
Details of each step
Engineering 46 0.5 23 Detailing the positions and checking the integrity of the exiting steel after adding holes
Marking of steel 26 0.5 13 The time required to mark the steel on site to ensure alignment with secondary member
Site set up 40 0.25 20 The time required to access power, get the drilling machine into position
Drilling time on site 40 1 40 Based on a steel thickness of 12mm and 1/4 hr per hole (see cutting speed rates)
Tapping on site 40 0.5 20 Half the time to tap
Tightening of bolts 40 0.2 8 High torques required so allowing for 5 mins per bolt and nut
Drill bits / taps N/A N/A 20 1 Drill bit and 1 tap at £10 each
Material costs (bolts) N/A N/A 10 Four bolts, buts and washers @ £2.5 each
         
Totals   2.8 £154.00  

Welded detail (Fully fillet welded connection to red oxide or galvanised steel)

The below table is based on making a welded connection of a new hollow section to an existing hollow section structure when both sections have a red oxide or hot dip galvanised corrosion protection.

Connection Requirements Rate/hr
(£)
Time
(hrs)
Step Cost
(£)
Details of each step
Engineering 45 0.25 11.25 Not much design work required apart from highlighting the position of holes
Apply for hot work permit 35 0.50 17.50 The issue time is set at 30 mins which can be much longer
Marking of steel 30 0.25 7.50 The marking of the steel is at a minimum for a welded connection
Site set up 30 0.50 15 Time to move equipment, power cords and get machinery ready
Removal of corrosion protection 40 1.0 40 The whole area for the weld needs to be removed by grinding and is time consuming
Performing of weld (inc Equip) 70 1.0 70 Based on a certified welder and equipment to make the connection
Fire watch during and after welding 30 2.0 60 Fire watches can be over longer periods but this is set at 2 hours after welding
Touch up of Galv / Paint 30 0.33 10 Replacement of the galv/paint will not be as good as the original finish
Non destructive testing 40 0.33 13.2 Testing of the weld required to prove load capabilities
         
Totals   6.16 £244.45  

BoxBolt connection (Based on four M16 BoxBolts connecting into 12.5mm)

The below table is based on making an end plate connection using four M16 BoxBolts.  The Hollow section column has a thickness of 12.5mm and therefore the BQ1G16 was selected.

Connection Requirements Rate/hr
(£)
Time
(hrs)
Step Cost
(£)
Details of each step
Engineering 45 0.25 10 Detailing the positions and checking the integrity of the exiting steel after adding holes
Marking of steel 26 0.25 6.5 The time required to mark the steel on site to ensure alignment with secondary member
Site set up 40 0.25 10 The time required to access power, get the drilling machine into position
Drilling time on site 40 0.25 10 Based on a flange thickness of 12.5mm and 1/4 hr per hole (see cutting speed rates)
Tightening of bolts 40 0.20 10 High torques required so allowing for 5 mins per bolt and nut
Material costs (bolts) N/A N/A 39.96 Four BoxBolts (BQ1G16) @ £9.99 each
         
Totals   1 £86.46