Hello and welcome back to kick of 2021!
Today we're going to discuss finishes. Both surface finishes and colors can impact your final product and part.
With that said, its very important to allow room to finish to size, allow room to finish to the desired surface finish, and temper expectations for color matching.
Unfortunately, this can mean it is safest to add room to your blanks to allow yourself room to finish to size. While this can add machine time and cost, it will ensure you're able to get the part to the place you need it to be so your customer is happy with the final product. It might also mean difficult discussions with customers to ensure everyone is on the same page and understands why some things may need to have a certain approach.
One thing that can come up is the color of finished parts. The example we're bringing up today is with food grade blue, and heat stabilized blue materials.
These materials are typically blue in color, however, the shade, hue, variant of blue can and often will vary from thickness (or diameter) to thickness (or diameter), as well as run to run and lot to lot. Unfortunately, this often means parts can vary in appearance but offer the same properties. This is the compromise needed to be made to ensure expectations are both realistic and met.
Additionally, another potential hurdle you might see is in regards to the factory surface finish on materials.
Materials are often extruded or cast to their near net size, sometimes they are provided as-extruded, however, it is more regular that materials are brought into the mill's stated tolerance range by techniques such as grinding, planing or skiving.While this helps ensure the material is falling within a size range that allows the user to know what to expect, it can also mean you might need to oversize your blanks to allow to finish to your desired surface finish.
Below is an example of the factory finish on material that has going through the planing process to ensure it falls within a certain thickness tolerance.
To expand on that idea, the other side (or edge in this case) to consider is the saw cut finish that will be left when the material is cut to size. This will again vary slightly, as every material and every order is different. However, the same idea of allowing room to finish to size and surface finish is an important consideration when you're planning your blank size and potential machine time on a job. Below is an example of what you might see on the saw cut finish of a material that was cut to size.
Hopefully these considerations help better plan to ensure all parties are giving themselves the best chance for success on finished parts being machined from cut to size blanks.