Understanding Micro-Joints

Micro-joints are thin areas of material left uncut, in order to keep your parts connected to the main sheet until they’re safely collected in the denesting phase. Without those tabs or connections, many parts could fall down into the equipment (and be damaged) or tip up during the cutting phase (posing a risk to the equipment).

There are two main kinds of micro-joints: Traditional and Undercuts.

1) Traditional micro-joints come from a top-side lead in, where the laser will bore into the material and then approach / complete the programmed cut lines. Once done, the parts are individually separated from the main sheet and may have a small bur or tab of material that needs to be sanded or grinded off.

2) Undercuts are basically the opposite. The lead-in takes place slightly inside the designed cut lines and when denested, it results in a small absence of material where the part breaks free from the sheet.

The size of micro-joints and whether or not they are necessary depends on the parts in question. Larger parts have little-to-no risk of falling down or tipping during the cutting process because they rest squarely on the toothed rows of our laser beds. In these cases, micro-joints aren’t necessary. Smaller or narrower parts that could tip or fall will require one or more micro-joints.

Below are OSH Cut’s best practices when it comes to micro-joint placement.

1) Utilize the fewest and smallest micro-joints necessary.

2) Allow the customer to specify their preferences regarding micro-joints in the order notes.

3) Choose the hypothetical “best-case scenario” according to our knowledge of the material behavior and the preservation of our equipment.

It’s important to note that material types, lengths of cuts, and thermal expansion also factor into these decisions. We’ve built systems to account for as many of these scenarios as possible to maintain tolerances.

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