I found this impact wrench
(https://bit.ly/2gjs68d) for sale on Machine Mart’s website. However, what I can’t understand is why Draper is listing the breakaway torque as being more than double the maximum reverse torque. Surely these are the same thing? Interestingly, the product manual lists it as 1200Nm! Anthony Pattinson Looking at the specifications, the torque setting is the same forward as backwards and is being listed as ‘max torque 4078kgf-cm/400nm/295 Ft-lb (+/- 10%)’. The breakaway torque is listed as ‘850Nm/625 Ft-lb’ and this would be in both directions. The breakaway torque is a higher value because it represents the force required to begin turning a fixing from the static position – this has to overcome the initial inertia, as well as the friction of the surfaces, which will be greater when the bolt or nut is in place. This initial breakaway torque will be delivered from the impact system within the unit.
As you observe, the manual for the CIW20LISF lists the breakaway torque as being 1200Nm and I am unsure why this is different from the sales listing of 850Nm.
The Draper battery powered impact gun set.