SUS Stainless Machining to JIS Drawings, Managed From Drawing to Delivery
We are a trading company. Send the drawing as it is, title block and all, and an engineer reads it and quotes it within 24 business hours. We buy the machining from a managed network of professional CNC shops, follow your order every week, inspect before packing and ship on our own paperwork.
- AISI / ASTM
- 304
- EN number
- 1.4301
- Family
- Austenitic
- Machinability
- 45 of 100
- Typical parts
- General machined parts, brackets, housings
Two halves, and the second one is what you pay for
A trading company is only worth buying from if it manages the work. Saying the first half plainly is what lets you check the second.
Trading company
- We buy the machining and sell you the finished part, on our own quote, order acknowledgement and invoice.
- We earn the margin between your price and the shop price. No service fee, no percentage added later.
- We own quality and schedule. A wrong part is ours to fix, not yours to chase across a border.
- We hold no machines and never describe a shop floor as ours.
Production management
- A managed network of professional CNC shops that we audit, visit and keep on performance.
- An engineer assigned to your order from the drawing review to the shipment.
- A weekly progress update in writing, with the stage the job is at and the date it is tracking to.
- Inspection before packing, with a report against your drawing and a seisekisho on request.
How the order runs
Five marks between your drawing and your dock. You talk to one engineer through all of them.
Drawing
Send the JIS drawing as it is, in Japanese or English, with the STEP file if you have one. An engineer reads the title block, the tolerance class, the finish marks and the certificate line before anything is priced.
Quote
A priced quote with a lead time within 24 business hours, with the questions that would otherwise surface at first article. You issue one purchase order to us and pay us.
Make
We place the machining with a shop in our network that runs that grade and holds that tolerance in production. The engineer on your order agrees the schedule, checks the material and visits the floor while it runs.
Inspect
First article against every dimension on the drawing, checks through the run, and a final inspection before packing. Anything out of tolerance does not leave.
Ship
Export packing, the inspection report, the mill sheet where you asked for one, and delivery on the terms stated on your quote. One shipment from one supplier.
What the network holds, grade by grade
Typical figures for the right shop on the right machine. The tolerance that applies to your part is confirmed on your quote, against your drawing.
| Grade | Processes | Typical tolerance | Note |
|---|---|---|---|
| SUS303 | Turning, sliding head, milling | h7 on turned diameters, ±0.02 mm milled | Free machining bar. Not for electropolishing. |
| SUS304 / SUS304L | Turning, milling, deep hole drilling | ±0.02 mm, h7 to 30 mm without grinding | The grade most drawings arrive with. |
| SUS316 / SUS316L | Turning, milling, electropolishing | ±0.02 mm, Ra 0.4 with an added operation | Wetted and vacuum parts. Passivation worth specifying. |
| SUS430 / SUS410 | Turning, milling | ±0.03 mm typical | Ferritic and martensitic, magnetic. |
| SUS420J2 / SUS440C | Rough, harden, grind | ±0.005 mm ground, Ra 0.4 | Sequence is part of the specification. |
| SUS630 (17-4 PH) | Rough, age, finish | ±0.01 mm after ageing | Contraction on ageing is planned in. |
Sizes, finishing, the full process list and the work we decline:capabilities. Grades, equivalents and what each one suits:materials. How every order is inspected: quality.
Eight things we read on a JIS drawing before it is priced
Most of the trouble on a Japanese drawing is not the geometry. It is the title block, the finish symbols and the standards the notes point at. This is the checklist the engineer runs before your drawing is placed with a shop.
- General tolerance classA drawing that says only JIS B 0405-m carries a different tolerance on every dimension size band, and JIS B 0419 adds the geometrical class H, K or L on top. A shop that skips the title block makes a looser part than the one you need.
- Surface finish symbolsCurrent drawings give Ra or Rz to JIS B 0601. Legacy drawings still carry triangle marks. The usual reading is one triangle Ra 25, two Ra 6.3, three Ra 1.6, four Ra 0.2, but we confirm it with the drawing owner before anyone prices a finish.
- Third angle projectionJIS B 0001 uses third angle projection, the same convention as ASME. A shop used to first angle views can read a feature on the wrong side and only find out at first article.
- Material call-out versus certificateThe drawing says SUS304. The bar on the shelf may be certified to ASTM A276 Type 304. The chemistry overlaps but the documents are not interchangeable, so state which standard the mill certificate has to name.
- Thread classM6 on its own is not a spec for a gauge-checked part. Give the JIS B 0205 pitch and the JIS B 0209 tolerance class, for example M6 x 1 - 6H, and say whether a go and no-go gauge result is required.
- Certificate levelSay up front whether you need an EN 10204 3.1 certificate, a JIS mill sheet, or traceability down to the heat lot. Adding it after the quote changes both the price and the material we can buy.
- Passivation and finishingPassivation is normally specified to ASTM A967 or AMS 2700 even on a JIS drawing. Electropolishing needs a target Ra as well, otherwise every shop assumes a different one.
- Magnetic permeabilityCold work raises the permeability of austenitic grades. If the part sits near a sensor or in a vacuum chamber, put the limit on the drawing, for example mu below 1.05, rather than in an email after the fact.
Look the values up yourself: general tolerance calculator,surface finish converter,grade converter.
Where SUS parts to JIS drawings end up
The sector matters less than the grade, the tolerance and the paperwork behind it.
Food and beverage machinery
Shafts, nozzles, fittings, guide rails, hygienic housings. SUS304, SUS316L.
Semiconductor and vacuum equipment
Chamber fittings, feedthroughs, gas line components, flanges. SUS316L, SUS304L.
Factory automation
Shafts, pins, guide rollers, brackets, sensor mounts, linear motion components. SUS303, SUS304, SUS440C.
Medical and laboratory equipment
Instrument bodies, jigs, fixtures, analyser components. No implants. SUS316L, SUS630, SUS420J2.
Pumps, valves and fluid handling
Stems, seats, bodies, spindles, unions. SUS316, SUS304, SUS630.
Instruments and optics
Mounts, carriers, spacers, small precision parts under 20 mm. SUS303, SUS304, SUS430.
Start with the part, not a form
Four fields and a file is enough for an engineer to tell you whether we should quote it. The full form asks about tolerance, finish, treatment and the documents you need, which gets you a firmer price at the first pass.
Prefer email? Send the drawing to sales at suscnc.com. Same engineer, same reply time.
Guides
Reference material for buyers pricing stainless parts from a Japanese drawing.
SUS303Se and SUS303Cu Compared with SUS303: Which Free Cutting Grade to Use
SUS303Se and SUS303Cu against standard SUS303: what selenium and copper change for finish, cold forming and corrosion, and what a drawing should state.
SUS Spacers and Collars to JIS Drawings: What Drives the Price of Small Lots
How stainless spacers and collars are made from JIS drawings in small lots: length and parallelism, bore and set screw details, stack-up and price breaks.
SUS Parts for Japanese Food Machinery: Choosing Grade, Finish and Design Details
Which SUS grade and finish suit machined parts for Japanese food machinery: SUS304 or SUS316L, Ra limits, radii, burr free edges and cleaning before packing.
Join the manufacturing network
We sell stainless parts to buyers working from JIS drawings and buy the machining from shops in our network. You receive a purchase order from SUS CNC with a drawing that has already been read, machine to print, report to our engineer once a week, and never deal with the buyer. Material and tooling suppliers are welcome too.
Shops and suppliers write to partner at suscnc.com. We reply within 24 business hours.
- One customer: usThe PO, the payment terms and the complaints all sit with SUS CNC. You never negotiate with a buyer abroad.
- A drawing already readJIS title block, finish marks and certificate line settled before the package reaches you.
- Paid on written termsAgreed before your first order. You are not asked to wait for the buyer to pay us.
- Audit, trial order, then regular workWe stand on your floor first, run a paid job of our own, then keep the work flowing on performance.
Questions buyers ask
Are you a trading company or a factory?
A trading company, and we say so plainly. We buy the machining from a managed network of professional CNC shops and sell you the finished part on our own paperwork. We hold no machines. What we add is the production management a pure middleman skips: the drawing is read by an engineer before it is placed, that engineer follows your order to the shipment, you get a progress update every week, and the parts are inspected before they are packed.
How are you paid?
On the margin between what you pay us and what we pay the shop. There is no quoting fee, no engineering fee and no percentage added at the end. The price on the quote is the price on the invoice.
Who do I place the order with?
With us. One purchase order, one invoice, one engineer as your contact for the life of the order. You never open an account with a machine shop and you never chase one.
Can you work from a drawing in Japanese?
Yes. Send it as it is. The title block, the JIS B 0405 tolerance class, the finish symbols and the certificate line are what decide the price, and the engineer reading it knows what they change. Notes that affect the process are translated for the shop before the order is placed.
Who sees my drawing?
Us, and the one shop that machines the part, never with your name attached unless you ask for it. Tick the NDA box on the quote form and the files wait with us until it is signed. Files are deleted after 12 months.
What inspection ships with the parts?
An inspection report with measured values against the critical features on your drawing, and a seisekisho in the Japanese format if you ask for one. A JIS mill sheet or an EN 10204 3.1 certificate where you specified it. Say what you need on the quote request so it is quoted in rather than added later.
What happens if a part is out of tolerance?
It is our problem, not yours. We measure before packing so it should not reach you, and if it does we resolve it with the shop while you deal with one company. The remedy that applies to your order is written on your quote and in our terms of sale.
Which grades do you cover?
The JIS stainless range: SUS303, SUS304, SUS304L, SUS316, SUS316L, SUS321, SUS430, SUS410, SUS420J2, SUS440C and SUS630. If the drawing names a grade outside that list, say so in the request and we tell you whether it is a fit rather than quoting it anyway.
How quickly do I get a quote?
Within 24 business hours, written by an engineer who has opened your file. There is no instant quoting engine here, because a number produced in nine seconds on a toleranced stainless part is a guess.