Tolerances get talked about a lot in mold shops, but many are still unaware about why it matters so much. A tolerance is how much a dimension is allowed to vary from the exact number on the drawing and tight tolerances mean less room for error. Loose tolerances mean more wiggle room and neither is automatically better but depends on the part.
If a mold is machined even a few thousandths off in the wrong spot, it can throw off wall thickness, cause parts to warp, or make assembly with other components a headache down the line. On a small part that might be a minor annoyance. On a large industrial mold, that same small error gets magnified, and fixing it after the fact costs a lot more than getting it right the first time.
This matters even more when parts need to fit together with other components, seal properly, or hold up under repeated stress. A cooling line that's off by a fraction can change how evenly a part cools, which affects everything from surface finish to how much it shrinks or warps after it comes out of the mold.
Machining equipment plays a big role here too. Older or less precise CNC setups just can't hold the same tolerances as newer 5-axis machines with probe systems built in for dimension checks. That's part of why the equipment a shop runs actually matters, not just their experience.
At American Tool and Engineering, tight tolerances is an aspect that is taken into consideration right from how every mold gets machined, checked, and tested before it ships. If you're looking for quality mold and engineering in Michigan, working with a shop that takes these tolerances seriously from the start will save you time, money, and a lot of frustration later.