Heads up: many models on this page are AI-generated or uploaded untested. They may be misconfigured for the intended application — check the dimensions and tolerances, and verify or edit the model before printing or relying on it.*
M3 And M4 Nut Holding Reach Wrench
A 130 mm double-ended stick for holding a hex nut behind a panel, inside an enclosure or deep in a robot frame while you drive the bolt from the other side. Each 4.5 mm thin head has a snug hex pocket: 5.6 mm across flats for an M3 nut and 7.1 mm for an M4 nut. A clearance hole (3.4 / 4.5 mm) runs through each head so the bolt tip can pass. A 7 mm thick handle gives you something to grip, and a 5 mm hang hole lets it sit on a pegboard.
M3 M4 M5 Captive-Nut Thread Checker
This 84 x 30 x 17 mm bench block holds real steel M3, M4 and M5 hex nuts (5.5, 7 and 8 mm across flats), which slide into side-loaded traps. To check an unmarked bolt, thread it in and see which size it fits. That saves you from trying the bolt in loose nuts over and over. Each station has a 3.4, 4.5 or 5.5 mm clearance bore. A relief channel underneath lets long bolts run out the bottom. Rows of 3, 4 and 5 dimples mark the sizes.