Component Design & Material References
These sources support general process and material understanding. They do not confirm SINTS supplier relationships, the grade of a pictured part or project qualification.
Metal Injection Molding
MIM combines molding, binder removal and sintering. An integrated shape still needs a review of the complete process and any final operations required by its drawing. This is why product pages distinguish forming the body from finishing critical interfaces.
BASF: MIM process overview →Conventional Powder Metallurgy
Conventional press-and-sinter production starts with compacting powder and then sintering the part. Material, shape, tooling and subsequent operations need to be considered together. A powder metal label alone does not define the tolerance, strength or final inspection requirements of a component.
EPMA: conventional press and sinter →Stainless Steel and Service Conditions
Stainless steel selection depends on the environment and surface condition, not only the alloy name. Cleaning, contamination and component design can influence corrosion behavior. A material record, the final finish and project-specific acceptance requirements should therefore be considered together.
Outokumpu: corrosion resistance →Where MIM and PM Material Specifications Come From
Material requirements for powder metallurgy and metal injection molding are published through recognised standards bodies rather than agreed supplier by supplier. This matters most at quotation stage, when two parties may use the same shorthand for different materials. Naming the standard and the grade together removes that ambiguity.
- MPIF Standard 35-MIM — Materials Standards for Metal Injection Molded Parts
Publishes mechanical and physical property data for the common MIM material families. Note that MPIF Standard 35 is a series issued for different product families — structural parts, self-lubricating bearings, powder forged parts and metal injection moulded parts — so the correct volume has to be cited. - ASTM B883-24 — Standard Specification for Metal Injection Molded (MIM) Ferrous Materials
The standard specification covering metal injection moulded ferrous materials. It applies to ferrous materials; non-ferrous and specialty grades are covered elsewhere. - ISO 5755:2022 — Sintered metal materials, specifications
The current edition of the international standard covering sintered metal material specifications more broadly, including press-and-sinter materials. - UNS numbers
Ferrous grades carry Unified Numbering System identifiers that make a specification unambiguous. 316L is UNS S31603 and 17-4PH is UNS S17400. Where a drawing names a grade, adding the UNS number prevents the common failure of two parties meaning different materials.
Design Guidance and Process Selection
Process selection guidance for powder metallurgy and MIM is published by industry associations, and reading it before a drawing is released is usually cheaper than discovering a constraint during tooling. The guidance is generic by design — it describes what a process family can and cannot do — so it informs the review rather than replacing it.
- EPMA (European Powder Metallurgy Association)
Publishes process descriptions, design guidance and material information for conventional press-and-sinter, metal injection molding and related powder routes. The conventional press-and-sinter process page is a useful starting point for understanding compaction and sintering as a sequence. - MPIF
In addition to the Standard 35 series, MPIF publishes design and material guidance for the powder metallurgy industry, including material designations used across the sector. - What guidance cannot do
No published guideline tells you whether a specific part at a specific annual volume will be economical on a specific route. That depends on geometry, tolerance structure, material, finishing and volume together, which is why the review stays part-specific.
Tolerance, Density and Finishing
Three properties decide most of the economics of a sintered part, and each behaves differently from its machining equivalent.
- As-sintered tolerance scales with the dimension.
A percentage tolerance applied across a part produces a large absolute value on a long dimension and a very small one on a short feature. Reading a drawing feature by feature is therefore necessary, and features that need tighter control are normally machined after sintering. - Density is a process characteristic, not a material constant.
Sintered density affects strength, hardness, wear behaviour, magnetic properties and how the part responds to heat treatment. It has to be characterised for the specific material and process route, then verified on first articles rather than assumed from a material name. - Near-net-shape is not net-shape.
Depending on the drawing, parts may still need de-burring, machining of critical bores or threads, heat treatment, tumbling, passivation, plating or coating. The objective is the shortest qualified route, not the fewest operations.
Corrosion and Service Conditions in More Detail
Corrosion resistance is a system property rather than a grade property. Alloy selection sets the starting point, but surface condition, contamination, crevices, the cleaning method and contact with other metals all influence the outcome. For stainless components this means the material record, the final finish and the project-specific acceptance requirements are usually reviewed together rather than independently. Where a part is exposed to cleaning agents, washdown or a specific medium, that exposure belongs in the request so the finish and the material can be assessed against it.
BSSA: British Stainless Steel Association →Route Selection Matrix for a Drawing Review
Published design guidance describes what a process family can do. This table does the opposite: it starts from a signal on the drawing and states what that signal usually points to, why, and where the same choice goes wrong. It is a review aid, not a rule engine — two signals in the same row frequently contradict each other, and that contradiction is exactly what the drawing review exists to resolve.
Drawing signals and what they point to
| Signal on the drawing | What it points to | Why | Where it goes wrong |
|---|---|---|---|
| Complex 3D geometry with undercuts, cross-holes or internal channels | MIM | Moulding sets the whole shape in one step; nothing has to be cut in from outside | Wall sections below about 0.5 mm may not fill, and distortion follows uneven mass |
| Simple axisymmetric or prismatic part, uniform wall, high volume | PM compaction | Die pressing is the lowest cost per piece of the forming routes at volume | Undercuts and cross-holes need a second operation, and density varies with fill depth |
| Tooth profile with an integrated hub or cam | PM or MIM | Both form teeth to near net shape; the choice turns on geometry complexity and density | Root density is lower than rim density, and the root is where a gear fails |
| Thread that must carry full load | Rolled thread, not cut | Rolling forms the thread from existing material, which needs density behind it — ≥7.0 g/cm³ in practice | Below that density the thread is cut, and the unit cost structure changes with it |
| A critical feature tighter than about ±0.05 mm | Add machining after sintering | Forming routes hold roughly ±0.3–0.5% as sintered, so the absolute value grows with the dimension | Applying that tolerance across the whole drawing turns a forming part into a machining part |
| Wall below about 1 mm over a large area | MIM, with a fill review | Cavity fill and distortion are the limits, not strength | Might not fill at all, and a section change is often cheaper than a process change |
| Weight-critical part | Aluminium or titanium, or a redesign | Density, not strength, sets mass: 2.70 g/cm³ for AlSi10Mg against 7.5–7.8 for steel | Titanium feedstock runs roughly five to ten times stainless, so it is specified when mass decides |
| Wear surface buried inside a mechanism | 440C or a hardened grade, at full density | Hardness only helps where density is high enough to support it | A hard alloy at low density wears faster than a softer alloy at full density |
| Part in contact with water, milk or cleaning agents | 316L, with density and porosity specified | The molybdenum addition is what keeps pitting out of the picture | Open porosity traps residue regardless of which alloy was chosen |
| Fewer than a few thousand pieces a year | Machining, unless geometry rules it out | As a rule of thumb, tooling amortised over that volume rarely closes | Tooling gets quoted anyway and the program stalls at the approval stage |
Tolerance figures follow the published MIM tolerance note and are planning arithmetic rather than achieved capability. Density and feedstock figures come from the SINTS material summary; cost figures are deliberately excluded because they belong in a quotation, not on a reference page.
What each route cannot do
| Route | Cannot do | What to do instead |
|---|---|---|
| PM compaction | Undercuts, cross-holes perpendicular to the pressing direction, internal channels | Add a machining operation, or move the part to MIM |
| PM compaction | Very thin walls over a large area | MIM, or a section redesign |
| MIM | Very large parts and heavy sections — mass, wall and debinding time are the limits | PM compaction, machining or a hybrid route |
| MIM | ±0.05 mm on many features without a machining step | Machine the critical features after sintering |
| Either forming route | A cosmetic A-surface straight out of the process without any finishing | Plan a finishing operation; polish the tool if the surface is the product |
| Either forming route | A material that is not available as a sinterable or mouldable powder | Machining or casting, or an alloy substitution reviewed with the designer |
The second column is the useful one. Most costly rework starts with a capability that was assumed rather than a process that was wrong: the route can do the job, but not the specific feature it was asked to hold. The press tonnages and inspection instruments behind these limits are listed on the capabilities page.
From General Guidance to Your Drawing
The product pages identify interfaces and questions for engineering review. Please provide the component drawing, mating arrangement, material requirements, expected quantity and acceptance criteria so the proposal can address the actual project.
Request a Drawing Review →Product Questions
Are these notes specifications?
No. They are review guidance — what to define and why it changes the route. Acceptance limits come from the drawing and the agreed inspection plan, not from this page.
Which note should I read first?
The one matching the feature that carries your function: a bore, a tooth, a sliding face or a heat-treatment window. The notes are organised by interface rather than by industry.
How do these notes connect to a quotation?
Each note ends with what to send for review. Those items are the ones that change the route or the price, so sending them at the first inquiry shortens the loop.