TESTED: Jessem rulers and squares
Words and photos: Raf Nathan
JessEm stainless steel precision rules
Along with their tasty router table equipment, JessEm have introduced some outstanding measuring tools. These stainless steel rules are available in imperial and metric in a wide range spanning 150, 300, 450 and 600mm.
The rules are made from 301 stainless steel with crisp markings that the manufacturers say are both engraved and etched, and with a satin finish on the surface for clarity. Against my reference tools the measuring scales were perfect on all rulers.
JessEm has patented its Flex Tab which is a series of framed angled cuts with the tab surface etched to give a slightly rough surface. This slightly grabs the wood and keeps the ruler in place quite securely so when marking it will virtually never slip. This is very useful as you can press down and make a line with a marking knife without fear of it wandering. It is a good feature.
The rulers are marked to read from left or right, and even better, are engraved on both sides. Manufacturing-wise this is not an easy thing to achieve accurately. For a job measuring both from left and right you can flip the ruler to get your readings with the zero point beginning from either the top or lower edge of the ruler.
The 600mm ruler was a favourite with me. It’s not a daily user but when you need a long ruler that is also dead straight this is superb.
You can always buy a cheap ruler – which these are not. However, the precision build of these with their satin finish, clear ruler markings and helpful flex tabs make them very useful and reliable. An MDF storage case is included.
JessEm stainless steel precision squares
Like their rules, JessEm stainless steel squares are available in metric and imperial. There are three metric sizes available – 150mm, 200mm and 300mm, all measured from the outside edge. The stainless steel blade has both etched and engraved ruler markings with a satin finish for easy reading.
The blades are set into a hefty black anodised aluminium stock and held with four large allen bolts. The stock thickness varies depending on the square size.
Against my reference equipment all the tools were perfectly square. Jessem say they set these to within 0.05mm deviation over the length of the blade. That’s really good.
There are scribing notches set along the blade at 1mm increments so you can draw a parallel line along an edge. The numbers for the notches are tiny and hard to read but the function is good. scratches on the polished surface. My verdict is that the squares would be much better without the flex tabs.
Once again, like the rulers, the squares have Flex Tabs to grip the work surface and stop the squares slipping in use. This works well although it hinders certain operations, such as when I was laying out three boards at once and found the flex tabs worked too well as it was hard to slide the boards along for alignment.
A big plus is the support tab built in at the end of the stock. This slides out as needed to allow the square to balance on its own. The mechanism for this is outstanding as it is embedded into the handle and the tab slides out via a spring-loaded knob. These squares are beautifully and precisely made.
Given the flex tabs have a textured finish, if you use the scribing notches to run a parallel pencil line, the tabs will scratch the workpiece. For most work that is to be sanded later this is no issue at all. If you were to lay out say a drawer handle on a polished surface though, the tab will leave tiny
Given the quality of build and accuracy, in addition to the artistic engineering involved with this level of toolmaking, I think the price is very reasonable. In fact compared to other high-end wood squares, these are cheaper. You can’t help but like these squares.
Review tools supplied by JessEm Tool Company, https://jessem.com