Top positive review
5.0 out of 5 starsAccuracy Tested Using a Torque Wrench Calibrator, Excellent Value and a Lifetime Guarantee + Adapter & Extension
Reviewed in the United Kingdom on 6 February 2014
I bought this item based on the excellent reviews, but wasn't expecting too much wow.
First of all it comes well packaged in a sturdy case. Included is a 1/2" to 3/8" adaptor (very handy) and a 100mm long 1/2" to 1/2" extension. The finish of the chrome vanadium of all parts is excellent and the wrench operates with a smooth and sturdy quality.
Despite all the good news upon inspection I still wasn't convinced, I needed objective results. Working for Delphi, a large automotive parts design/manufacturing company I popped over to one of the labs and pulled out the torque wrench calibrator, a Norbar Pro-Test Series 2 [...] costing approx £2000.
And these are the results, the first number is the indicated reading and the second number the measured value.
28 Nm - 28.8 Nm
42 Nm - 41.8 Nm
56 Nm - 57.2 Nm
70 Nm - 70.3 Nm
84 Nm - 85.1 Nm
98 Nm - 97.6 Nm
112 Nm - 114 Nm
126 Nm - 127.2 Nm
140 Nm - 142.1 Nm
154 Nm - 155.9 Nm
168 Nm - 168.3 Nm
182 Nm - 184.8 Nm
196 Nm - 196.3 Nm
210 Nm - 209.7Nm
Now I must admit, every time I tested it at a different setting the figures would vary slightly. The above values are an average of three tests at each setting.
Most torque values given in a Haynes book have a range of plus or minus 10%. This tells you there's a safety factor designed into most fasteners. Torque is a method of tensioning a bolt to give an axial load (basically the tension it creates to hold two or more parts together). Now there are a few variables that can affect the axial load of a screw threaded fastener for any given torque value. Namely variations in friction between the male and female thread and the underside of the bolt head and fixing face. If you're after a high level of axial load accuracy then you should be using a torque and angle method. This is where an initial torque is applied to fix the mating parts together and a rotation through a set angle of say 80 degrees gives the required axial load. This greatly reduces variations resulting from changes in the coefficient of friction between the threads, caused by lubrication or lack of and even rust. These methods are often used on an assembly line for torque critical items such as high pressure diesel injection system fuel pipes.
In summary the home/garage user really doesn't need to invest in overly expensive torque equipment. Assuming it lasts and continues to give relatively accurate results, this device is more than capable. It's best to store the item at the lowest torque setting as this prevents the spring from 'creeping' and stretching. DO NOT be tempted to set it more than half a turn below its minimum setting as this may just disengage it from the thread causing damage.
So an excellent purchase and if you register it at Silverline's website using the product code 633567 (which is not obvious to find on the box) it is guaranteed forever!
Well done Silverline, you really have marketed/manufactured an excellent product.
