Made in South Africa: King Bull develops soft jaws and tap wrenches

The crisis that the world is experiencing has had a devastating effect on all aspects of life and has changed the way we think.

I recently asked in my last editors comment whether there can be positives that we can learn from as a result of this difficult period in our lives? I say yes. We need to be optimistic and down the line we will all benefit. With virtually every country going through some form of lockdown, localism has almost become a new way of life. Looking after those nearest and dearest to you has been re-enforced by the limited movement that has been allowed. Economically it has been disastrous. And this is the point. To get our economy going again let us think and support local. After all, the old cliché does say that charity starts at home.

It is therefore refreshing to announce that King Bull Industrial Supplies and Sales, an importer and distributor of threading tools (taps and forming taps) manufactured by German specialist manufacturer Schumacher Precision Tools GmbH, has developed and manufactured a range of soft jaws for use on lathe chucks and a range of hand tap wrenches – South African designed and manufactured.

King Bull Industrial Supplies and Sales have developed and manufactured a range of soft jaws

“A positive from this crisis is that for most of us we have been afforded the opportunity to have quality time with our family over a much longer period than we would not normally have because of the busy lives we lead. Likewise in our business lives. We are always too busy and don’t find the time to develop ideas that we have had in our head for some time. This changed when we went into lockdown and many businesses and manufacturing companies were forced to close. Some of us were proactive and got busy with developing our ideas that we have been sitting on for so long,” commented King Bull’s Matt Mayhew, who is also the Managing Director of CNC machining and general engineering company Matthew and Son Engineering.

“The idea to develop and locally manufacture a range of soft jaws and tap wrenches arose purely out of frustration. As far as we are aware none are now manufactured in South Africa. As a result you have to rely on the importer who generally does not carry a full range and would not have the product size that you are looking for. This would add on extra time as it was imported and when you did eventually receive the product, the quality was very questionable because it had been imported from, for example China.”

Made in South Africa: Soft jaws

“During lockdown many products and components could not be imported and this predicament will carry on for some time. Most companies in the engineering industry are back in operation, albeit on a limited basis, and will need engineering consumables to keep their equipment running. Because the importer has limited stock I foresee a problem in the near future.”

“Manufacture locally and our product development ideas suddenly have a very real relevance.”

Soft jaws
“The most common workholding device for turning centers is the three-jaw chuck. Setup people remove and replace top tooling (jaws) during every setup, and this task can be relatively simple if quick-change chucks are used. However, the vast majority of three-jaw chucks used on turning centers are not quick-change chucks. Therefore, mounting and replacing the jaws will take much longer.”

“With most three-jaw chucks, two socket head cap screws are used to clamp each jaw (with a long tee nut) to the chuck’s master jaw. Thus, a total of six screws are needed for the three jaws. The master jaws on the chuck have small serrations that match serrations on each top-tooling jaw. These serrations are critical to the accuracy of the soft-jaw.”

“It is also important that the jaws be mounted in such a way that they clamp near the middle of the chuck stroke and, of course, jaws must be mounted in those serrations that allow the jaws to clamp the workpiece. This can be a complicated task, especially for beginners. If the jaws are not mounted properly, the whole task of mounting the jaws must be repeated. Because the serrations are so small, the setup person won’t know something is wrong until all three jaws are mounted.”

Adjustable tap wrenches developed by King Bull Industrial Supplies and Sales and manufactured by Matthew and Son Engineering

“Setup people eventually get good at approximating the position of each jaw so that it will clamp at the appropriate diameter. However, this skill comes at the price of much trial-and-error. Mounting jaws can be very frustrating for entry-level setup people as they try to figure it out.”

“This is where damage to the soft jaws occurs and tolerances are lost. Every component that you are machining on your turning center should have its own set of jaws.”

“Companies also try and save on costs and many have done their own handy-work on the jaws. Or they have done this handy-work because they have not been able to get supply of the size that they are looking for.”

Off the shelf stock of nearly 100 different sizes of soft jaws
“We are now marketing a range of soft jaws that have been manufactured by Matthew and Son Engineering. Nearly 100 different jaws are available because soft chuck jaws are required in various heights, lengths, widths and hole-to-front dimensions for use with most manual and CNC lathe chucks.”

Soft jaws in production

“All the jaws have been manufactured in material (EN8/C45) supplied by ArcelorMittal and the jaws are available in sizes from 6” to 24”. We will be carrying a large amount of standard stock sizes so you can virtually have same day delivery and our pricing is more than comparable to any imported product. Specials are also available on request.”

Pie jaws and aluminium sets
“We have taken great care in quality machining of the jaws, especially in the serration of each jaw. Going forward we will soon be adding a range of pie jaws and aluminium sets to the product range.”

Adjustable tap wrenches
“Two years ago, we were appointed the distributor in South Africa of threading tools (taps and forming taps) manufactured by German specialist manufacturer Schumacher Precision Tools GmbH. This product is really being recognised as a quality product and sales have grown tremendously.”

“But what we found was that the hand tap wrenches used in conjunction with the taps were all being imported and were of very poor quality and design. A number that we have used in our own manufacturing have actually broken.”

“We have now designed our own tap wrench, done a prototype, which worked successfully and now gone into production.”

Adjustable tap wrenches in production

“Again Matthew and Son Engineering are doing the manufacturing and they are using locally supplied material. We use EN19T for the centre body, tool steel for the inserts and carbon steel for the handles. All have been heat treated, tempered and hardened for strength.”

“We are manufacturing eight different sizes, from No.0 (M1-5) to No.7 (M52-80). We know we have manufactured a product that will last a lifetime but at least we know the operator will be confident when operating one in conjunction with a Schumacher tap.”

Matthew and Son Engineering
“These two products we are referring to as our lockdown products. Many variations of the soft jaws and tap wrenches, make up the ranges. They are South African designed and manufactured by Matthew and Son Engineering, a South African CNC machining company.”

“The crisis that the world is experiencing has had a devastating effect on all aspects of life and has changed the way we think. Lets hope that many others in South Africa do the same.”

For further details contact King Bull Industrial Supplies and Sales on TEL: 011 609 5603 or email