and between them grooves 19 20 which are so deep that where a tooth 10 upon a sawblade is contacted and deformed by a ridge 17 on the one setting roller 14 the corresponding groove 20 on the other setting roller 15 should be so deep that the tooth will not touch the bottom of the groove the shape of the ridges may be chosen to fit the intended shape of the tooth after setting and may preferably have a convex or rounded edge to avoid sharp impressions which may disturb the chip flow or be a starting point of cracks the angular distances between the ridges do not have to be equal but may be chosen to correspond to the tooth pitch in a group of teeth with variable pitch the contact with the setting rollers should not contribute to the forward feeding of the sawblade which is preferably fed by a separate feed mechanism in front of or behind the setting rollers this makes it possible to adjust the rotational speed of the setting rollers relative to the feed mechanism in order to ensure that each ridge 17 18 contacts the corresponding tooth 10 in the correct position this is possible by measuring the position of the front edge of.