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Friday, 25 May 2012

Craig Sommerfield - Inventor of the Kreg Jig

This is Craig Sommerfeld, a really nice guy from Iowa who had a great idea and followed it through. in 1986 Craig was building some kitchen units for his home and needed a better way of securing his face frames to the units than using nails and filler. Being a tool and die maker, he fashioned himself a J shaped piece of aluminium with an angled steel tubular insert so that he could accurately and repeatably drill shallow diagonal 'pocket holes' to accept screws inserted from the inside of the cabinet. And so Craig's Jig - later to become the Kreg Jig, was born.

 After enough, 'ooh now that's clever, can you make me one too?' comments, Craig took to making them during the week and then selling them at weekend woodworking shows. This is the graft bit, working shows is really hard work, but it pays dividends - as Craig says (if memory serves) "you get to look into peoples faces and see the moment when they get it, answer their questions and really understand what they want'. After thousands of demonstrations and a lot of work refining and perfecting the product into a complete system, the latest 4th generation Kreg Jig looks like this:

 The plastic bits are actually glass reinforced nylon and are virtually indestructible, the frame can be clamped or screwed to a bench for producing components (as shown above) or you can use the integral clamp to fix it directly to the workpiece. For situations where you need to take the jig to the workpiece and space is limited (repair work for example) the drill guide block can be removed and installed in a Kreg portable base unit, which locates over the side of the workpiece and can be adjusted for material thickness by sliding the guide block in or out and securing it with the brass screw.

Once the pockets are formed the two pieces can be clamped in place (genuine Kreg clamps work perfectly but in a pinch you can get by with standard ones) and secured together with screws. There's no waiting for the glue to dry and once the screws are driven home the clamps can be removed and you are onto the next joint. While we are at this point, there would be no advantage in adding glue to this joint because you can't glue endgrain - hence it would traditionally be done with a mortice and tenon or half-lap joint which give large long-grain to long-grain contact surfaces

 All Kreg products are solid, durable and robust, a result of the guy who invented the system and owns the company standing in front of his customers and selling it to them week in week out for years. The system is simple, fast, accurate and works beautifully. Whether you are making your first table and find traditional joinery a bit daunting, or a top designer-maker looking to improve the speed and efficiency of producing jigs and forms, Kreg pocket hole joinery may just be the answer.

For those that want more discrete pocket holes there is the Kreg Micro guide block, which simply replaces the guide block in the standard set up and produces 25% smaller pocket holes. Using the pan head screws the head of the screw is still fully concealed and the holes are plugable.

The next logical step is to go bigger, so for construction sized workpieces the new Kreg HD jig (announced earlier this week) is due to be launched this summer:


  1. Does anyone know why they moved away from the lever in the front which was on the K3 system and back to the front which was a return to the K2000 type jig?


    1. Hi Don, I think there was a copyright dispute about it, not sure of the details but I believe the case was thrown out in the end.