Chisel and plaine iron width variance

Their 3mm blade is the same as 1/8″ so sizes are not really precise.
In fact their online description says sizes a nominal .
Have you asked Veritas (lee valley)? They are generally very good at responding to such questions.

Do you woodwork with a micrometer?

Veritas offers some tools, e.g. plough planes, in pairs of left hand and right versions, with the supposed benefit of one of the planes to be used with the grain. It’s of course not uncommon for grain direction to change, which would call for first using one of the planes and then the other. If tolerances are ±0.01″, then it’s perfectly feasible to have quite the discrepancy in width of a groove where the planes meet. Running a 6.2 mm left replacement blade into a more narrow part of a nominally 6 mm wide groove, resulted for me in bad spelching. Being by myself fairly good at generating imperfections, there is no need for the tools to add any.

Thinking that the 6.2 mm one was just bad luck, and not completely without merits for fitting 6 mm plywood (seldom 6 mm), I ordered a new one, and was apparently in luck, as it actually is 6 mm. Then, after having read this exchange, I measured the widths of all my 26 plough plane blades. The ones coming with the planes were, perhaps not very surprising, ¼”. The 10 mm ones were 10 mm; all the other blades were off, with one deviating by 0.23 mm. Thankfully the discrepancies were consistent within the pairs. The metric blades were all above their nominal widths, with opposite for the imperial ones. The wide blades 10, 12, 16, and 18 mm were all very close to nominal values. Finally, all left hand metric blades came in small plastic bags, while all imperial and some right hand metric were neatly wrapped in little paper envelopes – acknowledging the company’s awareness of its bread being mainly buttered on the transatlantic side.

Those who, like me, have multiple chisels of the same widths, to be able to change when one loses sharpness, might wonder if a tolerance range of 0.02″ really leaves sufficiently accurate mortice holes.

In a rather hagiographic blog post of some years, Mr. P. Sellers describes the detail into which Veritas go in order to achieve accuracy and precision (plane soles for instance), which begs the question: why not plane blades? Particularly since there’s a company not that far west of Toronto, capable of the most laudable accuracy and precision.

Finally, and please forgive me Larry, but isn’t the comment on a micrometer just the teeniest tad of rich, coming from someone who allegedly milled his own set-up blocks.

Cheers
Sven-Olof