There are guidelines to follow when designing a powder metal part to ensure that it is well engineered and economically produced. Below are some of the more common design details that must be considered.
If you have design questions about your particular part, please contact us.
Edges
- Avoid feathered edges. Chamfers are preferred.
Spines
- Avoid narrow, deep spines.
Corners
- Avoid sharp corners. Rounded corners permit uniform powder flow in the die, increased part strength and eliminate stress risers.
Holes
- Can be round or D-shaped. Blind holes, blind steps in holes and tapered holes are okay.
- Lightening holes are frequently added to large parts.
- Side holes are produced after sintering
Wall Thickness
- In general cannot be thinner than 0.060 inch (1.52mm) and not to exceed 8:1 wall thickness to length ratio.
Flatness
- Total flatness depends on part thickness. Thin parts tend to distort.
Tapers and Drafts
- Not required.
Fillets and Radii
- Generous fillet or radii are best. Parts with generous fillet or radii are more economical, longer lasting, more easily produced and have greater structural integrity.
Countersinks
- A 0.010 inch (0.25 mm) nominal flat is required.
Flanges
- A small flange, edge, or overhang is preferred. Bottom flange edges and juncture radii should be generous.
Undercuts
- Undercuts perpendicular to the pressing direction can only be made with a secondary operation. A curved undercut is an alternative.
Slots and Grooves
- Curved or semicircular grooves are allowed to a maximum depth of 20% of overall part length.
- Rectangular grooves are allowed to a maximum depth of 10% of overall part length or thickness if the surfaces parallel to the pressing direction have up to a 12° draft and all corners are radiused.
- Annular grooves must be machined.