Why Should You Use An Unbrako Premium Socket Wrench?

Scroll down for our free Hex Wrench Guide

We at Earnest Machine receive many questions from our customers regarding our line of Unbrako High Strength Socket Screws, but one area our customers commonly overlook is the Hex Wrench line used to install these socket screws.  

The Hex Wrench is the tool used to install the socket screw into the threaded hole. For smaller size screws, it is the wrench used to achieve the final tightness in the assembly. The use of a high quality hex wrench is just as important in achieving a tight, reliable assembly as the quality of the socket screw.  

Hex Wrenches (also called Allen Wrenches or a Hex Keys), are commonly found in low strength or non-critical applications. Those who have assembled furniture from Ikea, Amazon, Walmart, etc. are most likely familiar with these wrenches as they are normally included in the packaging. Though perfect for those applications, we don’t recommend pairing an inexpensive wrench with a high strength socket screw for a high strength critical application. These low quality wrenches will not achieve the torques required for proper assembly of high strength socket screws.

Even if a socket drive hex key is going to be used to achieve the final tightening in an application, we recommend the use a high quality hex wrench to initiate the assembly and to achieve the initial snug fit in the assembly.

There are three critical characteristics that makes a quality hex wrench: 

1. The first is that they are made from a high quality alloy steel. Alloy steels provide toughness and strength which are essential in producing a hex key that will not distort when the socket screw is tightened. 

2. The second critical characteristic is the quality of the heat treatment. Achieving a uniform high through hardness is essential in ensuring that your socket wrench will not round out at the hex corners, or worse, twist before sufficient tightening is achieved in the socket screw. 

3. The third critical characteristic of a quality hex wrench is the dimensional tolerances the hex is made to. The tolerance of the width across the flats, the form of the hex, and the quality of the surface finish are all essential in ensuring the hex key will be able to withstand the installation torques without causing the socket or the key to round out. The tips of the wrenches also need to be flat points with a smooth chamfer to ensure the wrench fully engages in installation.

You can be confident in the quality of the Unbrako Wrenches that are supplied by Earnest. All of our wrenches are marked with the Unbrako name and have the hex size stamped into them.  Unbrako uses high quality alloy steel that is through hardened to a high hardness on all sizes of their wrenches to ensure that they provide excellent strength and toughness. 

At Earnest we offer two styles of hex wrenches in both inch and metric sizes. The two styles we offer are called the “short arm” and “long arm” wrench.

The short arm is the wrench style that we are all familiar with and is considered the industry standard.

We also carry a long arm style. The extra-long arm provides two added advantages over the standard short wrench:

1. Added reach to fit the wrench into deep hole applications. 

2. Achieve higher torques. The higher torque provides a tighter assembly than can be achieved with a standard or short arm wrench.

One thing to remember is the different head styles of socket screws can require a different size Hex Wrench for installation. For example, a ¼” diameter hex socket screw uses a different wrench size than a ¼” set screw or a ¼” flat head socket screw. Be sure you are using the correct size hex wrench for the size and style of socket screw that is being installed.

Earnest offers a free download on our website that lists the wrench size that is needed for each head style and diameter of socket screws we carry. Download our free guide to ensure you are using the wrench designed for the size and style of socket screw you are installing.