kevinlongisland wrote:
hello all. i've had some parts made for my rock crawlers using water
jet. but the water jet leaves abrasion marks and also there are
scratches on the material most likely from handling. anyway, i'm
trying to increase my parts quality to this level:

http://www.thecrawlerstore.com/image...hop_bumper.jpg

what are some good cutting process and material specs to get this type
of part quality. thank you for all your input.

I am no expert, so my advice is worth what you pay for it, but I have
seen many manufacturing processes over the past years and it often
surprises me at the look of the finished part compared to how the same
part looks as an unfinished part.

The bumper you illustrated probably was not done in a one step
operation, but saw many different processes to achieve the look that the
finished part has. If I were to guess, I would say the the part was made
like this.
1. Blanking and/or blanking and cutting of the slots.
2. Drilling and chamfering of the holes.
3. Bending of machined blank to fit mounting brackets.
4. Finishing (buffing, vibratory finishing or abrading)
5. Plating or anodizing.

It is very difficult to take a raw piece of metal (or any material,
wood, plastic, etc.) and form it to its finished shape without leaving
some type of machining or handling marks on the raw part. A finished
appearance part like this almost always needs some type of secondary
finishing operation to give the part its pleasing "finished" look.