Injection Molding
Tooling and molding for your repeat plastic parts.
AISI 303 · UNS S30300 · EN 1.4305
303 Stainless Steel for Your Turned & Machined Parts
For your 303 stainless steel machining project, start with the turned features, threaded interfaces and environment your part must serve.
Use the free-machining grade when it fits your drawing and acceptance requirements. Review corrosion exposure and any joining before choosing 303 over another stainless grade.
Identify Your 303 Material Before Quoting
Stainless steel 303 is an austenitic free-machining grade. Its sulfur modification supports chip breaking, but your material choice must also account for the actual exposure and manufacturing sequence.
Use SS 303 or 303 stainless as search names; retain the full grade and product specification on your drawing and purchase order.
| Search name | Order check |
|---|---|
| AISI 303 / UNS S30300 | Confirm the specified standard and delivery condition. |
| EN 1.4305 | Common European correspondence; confirm product form and specification before substitution. |
| 303 stainless steel ASTM A582 | Confirm applicable revision, size, condition and agreed certificate scope. |
3 Questions Before You Choose 303
Your machining features
Are turned lands, cross holes, threads and repeat small components the primary manufacturing need?
Your service environment
What fluid, cleaning, temperature, moisture and dissimilar-metal contact will the part see?
Your joining route
Does your design need welding or heavy forming? Review another grade where the process conflicts with 303.
303 Stainless Steel Turning Services
Connect 303 stainless steel turning to the shoulders, grooves, bore and thread that control your assembly. Mark the datum and runout relationships rather than applying the same tight tolerance to every diameter.
For 303 stainless steel shafts, define bearing lands and final straightness. For 303 stainless steel bushings and 303 stainless steel spacers, identify mating diameters, length relationships and burr limits.
303 stainless steel screw machine parts and 303 stainless steel Swiss machining require a review of bar form, feature access and the proposed production route.
CNC Turning → · Swiss Turning →
303 Stainless Steel CNC Machining
For 303 stainless steel milling, relate pockets, wall sections and hole patterns to the workholding and inspection datum. Identify inaccessible edges that need a separate deburring operation.
303 stainless steel drilling needs a clear depth and intersection requirement. State whether a hole is blind, through, cross-drilled or part of a threaded interface.
CNC Milling →
Define Your 303 Threaded Parts
For 303 stainless steel tapping, give the thread standard, class, useful depth and entry condition. Agree how internal burrs and intersecting holes will be checked.
For 303 stainless steel threaded parts, confirm the finished thread after cleaning, marking or any specified surface process. Call out mating hardware and functional fit requirements.
DFM & Drawing Review →
303 Stainless Steel Composition & Properties
Read 303 stainless steel properties against the product specification and condition. The following supplier type analysis supports a material discussion; your lot certificate and controlled order requirements govern procurement.
Selected 303 Composition Ranges
CarTech® 303 reference · mass % · range segment
01020%
Chromium 17–19%
Nickel 8–10%
| Element | Supplier type analysis · mass % |
|---|---|
| C | ≤0.12 |
| Mn | ≤2.00 |
| P | ≤0.200 |
| S | ≥0.150 |
| Si | ≤1.00 |
| Cr | 17.00–19.00 |
| Ni | 8.00–10.00 |
| Fe | Balance |
Selected CarTech® 303 datasheet. The PDF lists sulfur as a minimum; do not treat the web summary’s conflicting maximum label as the procurement limit. Not an LK batch analysis.
Supplier 303 datasheet →The cited supplier lists specific gravity 7.83 and approximately 160 HB after its stated annealing treatment. These are reference values, not universal stock guarantees. 303 is not hardened by heat treatment; cold work can alter strength and hardness.
303 vs 304 vs 316: Compare the Actual Job
| Decision | 303 | 304/304L | 316/316L |
|---|---|---|---|
| Machining focus | Free-machining modification; review feature/condition | Review chip control and fabrication scope | Review exposure and machining condition together |
| Welded assembly | Supplier does not recommend welding | Evaluate exact grade and weld procedure | Evaluate low-carbon requirement and weld procedure |
| Corrosion exposure | Confirm environment before substitution | Review service medium and cleaning | Review actual chloride/chemical conditions; name alone is insufficient |
| Your approval | Keep specified material and finish | Do not substitute from similar appearance | Do not assume a general “marine grade” guarantee |
4 Drawing Checks for Your 303 Part
01 · Datums
Locate the part from functional reference faces
01
Relate turning and milling datums before the second setup. Identify the bearing or assembly references.
Show locating faces, bore axes and the inspection setup. The pictured fixture illustrates access; your drawing supplies the actual dimensions.
1.4305EN correspondence for 303
A material identifier, not a dimensional or substitution approval.
Read the source and conditions →
02 · Internal burrs
Make the internal intersection accessible
02
Specify cross-hole, thread and blind-pocket deburring access. Define how hidden burrs will be accepted.
Show the cross-hole intersection and how its edge can be reached for deburring and inspection.
≥ 0.150%Sulfur · mass % · supplier chemistry minimum
Carpenter 303 reference. Sulfur supports free-machining behavior; it does not guarantee a burr-free intersecting passage.
Read the source and conditions →
03 · Thin sections
Support the section before removing stock
03
Review clamping support and the order of material removal. Protect critical relationships from distortion.
Connect wall geometry, support and finishing sequence. Confirm stock condition before choosing feeds, tools and clamping.
17–19%Chromium · mass % · supplier chemistry range
Material chemistry is background for grade identification, not a wall-thickness or workholding guarantee.
Read the source and conditions →
04 · Surface condition
Separate appearance from service suitability
04
Agree cleaning, visible faces and final acceptance after the specified surface route.
Define sealing faces, handling protection and cleaning. Review corrosion and joining needs before replacing another austenitic grade.
8–10%Nickel · mass % · supplier chemistry range
Read with the complete Carpenter 303 chemistry; appearance alone cannot certify the alloy or corrosion performance.
Read the source and conditions →Choose the Final Surface Before Release
For 303 stainless steel passivation, confirm the cleaning method, process compatibility and required evidence for the actual material and geometry. A treatment name is not a corrosion-life guarantee.
303 stainless steel polishing needs an agreed visible-face and appearance reference.303 stainless steel laser marking requires location, content, contrast and acceptance criteria.
Brushing & Polishing → · Laser Engraving →
4 Records for Your 303 Order
Material identity
Grade, product standard, delivery condition and agreed material record.
Critical relationships
Datums, mating sizes, threads and the finished inspection state.
Surface acceptance
Cleaning, marking, appearance and any specified treatment evidence.
Release identification
Revision, lot identity, exceptions and protective packaging.
From Your 303 Prototype to Repeat Parts
For 303 stainless steel prototype machining, define what the first parts must prove and how the intended production material and condition will be represented.
1 · Fix the baseline
Confirm drawing revision, material, dimensions and finish.
2 · Review the sample
Assess fit, hidden burrs, appearance and evidence scope.
3 · Retain the release
Keep the approved revision, inspection plan and change record.
5 Inputs Behind Your 303 Machining Quote
For your 303 stainless steel machining quote, compare the same finished-part scope. When reviewing a 303 stainless steel CNC parts manufacturer, ask how the proposed route addresses your drawing and acceptance requirements.
Stock & condition
Product form, blank size and specified delivery condition.
Feature access
Turned and milled setups, deep holes and internal burr removal.
Quantity
Trial parts, repeat demand and release pattern.
Surface route
Cleaning, polishing, marking and appearance approval.
Evidence & packing
Inspection, material records and handling protection.
Your Questions Before Ordering 303 Parts
303 vs 304 stainless steel: which fits your part?
Compare machining features, corrosion exposure and joining. Keep the exact grade on your drawing; a free-machining choice is not an automatic substitute.
303 vs 316 stainless steel: what controls the choice?
Use the actual fluid, temperature, cleaning and moisture conditions. Specify your required material and review any proposed alternative.
Is 303 stainless steel magnetic?
Do not use a magnet alone to verify grade or condition. Material identity should follow the agreed specification and certificate; processing can affect magnetic response.
Does 303 stainless steel rust?
It can corrode in unsuitable conditions. Review exposure, surface contamination, cleaning and retained moisture instead of assuming all stainless grades behave alike.
Can 303 stainless steel be welded?
The cited Carpenter datasheet does not recommend welding because the sulfur modification can create welding problems. Review a different material or an explicitly qualified joining route.
Can 303 stainless steel be passivated?
Review a compatible cleaning/passivation route and evidence scope for your actual part. Confirm treatment requirements before final acceptance.
What is 303 stainless steel used for?
Review shafts, bushings, spacers and threaded components where machining is prominent and the service environment suits the specified material.
How much does 303 stainless steel machining cost?
Send the drawing, material condition, quantity, finish and required records. Geometry, setup access, material removal and acceptance scope affect your quotation.
6 Inputs for Your Custom 303 Stainless Steel Parts
For 303 stainless steel machining services, provide a controlled scope so your supplier can review the 303 stainless steel machined parts you need.
Drawing
Controlled revision and CAD when available.
Material
Grade, standard and condition.
Features
Critical sizes, datums and thread requirements.
Quantity
Prototype and repeat quantities.
Finish
Cleaning, appearance and marking requirements.
Records
Inspection, material identity and packing scope.
