Steel, finish and quality control
Two kinds of steel. Each picked for the job it does.
Four locked quality tiers: Economy AISI 410 · Clinical AISI 420 · Premium AISI 420-440C · Executive AISI 440C. Hollowware and sterilization containers: Clinical AISI 202 · Premium and Executive AISI 304. All instruments and hollowware passivated.
On this page, five steel grades are grouped in two ways: three hardened grades across four instrument tiers, and two formed grades for hollowware and sterilization containers.
Which line is for which buyer
Scroll the table sideways to see every column.
| Line | Steel | Finish | Quality control | Typical buyer |
|---|---|---|---|---|
| Economy line | AISI 410 | satin, passivated | sample: visual + dimensional | training institutes, veterinary, volume / UN-NGO tenders |
| Clinical line | AISI 420 | satin, passivated | sample + boil test | hospitals, distributors |
| Premium line | AISI 420-440C | fine polish, passivated | tighter sample + hardness test | quality-focused distributors, private label |
| Executive line | AISI 440C | mirror polish, passivated | 100% inspection + laser mark | OEM flagship / top private label |
| Hollowware: Clinical | AISI 202 | Bright / mirror polish | Every piece inspected: finish and hand-finishing, polish, edges, size, shine and overall structure, and the buyer's own design or logo where one is specified. Anything that does not meet the specification is corrected rather than passed. | hospitals, distributors |
| Hollowware: Premium and Executive | AISI 304 | Bright / mirror polish | Every piece inspected: finish and hand-finishing, polish, edges, size, shine and overall structure, and the buyer's own design or logo where one is specified. Anything that does not meet the specification is corrected rather than passed. | quality-focused distributors, private label · OEM flagship / top private label |
Hardened by heat treatment
Instrument steels
These steels are hardened by heat treatment, and that hardness is what lets a ground edge or a jaw stay sharp through repeated use and resharpening.
Economy
410
AISI
- Finish
- satin, passivated
- Quality control
- sample: visual + dimensional
- Typical buyer
- training institutes, veterinary, volume / UN-NGO tenders
Clinical
420
AISI
- Finish
- satin, passivated
- Quality control
- sample + boil test
- Typical buyer
- hospitals, distributors
Premium
420-440C
AISI
- Finish
- fine polish, passivated
- Quality control
- tighter sample + hardness test
- Typical buyer
- quality-focused distributors, private label
Executive
440C
AISI
- Finish
- mirror polish, passivated
- Quality control
- 100% inspection + laser mark
- Typical buyer
- OEM flagship / top private label
Different steel for a different job: AISI 202 and AISI 304 are chosen for form and corrosion resistance, 420 and 440 for holding a cutting edge.
Formed, not hardened
Hollowware and sterilization steels
These are stainless steels that press and draw into deep shapes without cracking, and stand up to repeated washing and autoclaving. That is what a tray or a sterilization box needs. An edge is not.
Both grades are stainless steel, and the line you order is what sets which one you get: AISI 202 on a Clinical order, AISI 304 on a Premium or Executive one. Hollowware starts at Clinical: there is no Economy line in these two grades. AISI 304 resists corrosion better. Neither is hardened by heat treatment, so neither is harder than the instrument grades.
Clinical
202
AISI
- Used for
- Trays, bowls, kidney dishes, sterilization boxes and containers, on a Clinical-line order.
- Finish
- Bright / mirror polish
- Passivation
- Passivated
- Quality control
- Every piece inspected: finish and hand-finishing, polish, edges, size, shine and overall structure, and the buyer's own design or logo where one is specified. Anything that does not meet the specification is corrected rather than passed.
- The steel
- A chromium-manganese-nickel stainless steel: it replaces about half of 304's nickel with manganese. It draws and presses well and has a higher yield strength than 304, but it resists corrosion less well: in damp, salty or chemical conditions it can stain or pit sooner.
Premium and Executive
304
AISI
- Used for
- Trays, bowls, kidney dishes, sterilization boxes and containers, on a Premium or Executive order.
- Finish
- Bright / mirror polish
- Passivation
- Passivated
- Quality control
- Every piece inspected: finish and hand-finishing, polish, edges, size, shine and overall structure, and the buyer's own design or logo where one is specified. Anything that does not meet the specification is corrected rather than passed.
- The steel
- The 18/8 chromium-nickel grade, and the standard steel for hollowware and sterilization containers: it forms a more durable passive layer and holds its corrosion resistance through humid, salty and acidic conditions and repeated autoclaving.
The line you order sets which of the two grades an article ships in, and it is confirmed on your order. The inspection step is the same for both grades, because it is the article that is inspected and the same tray ships in either steel off the same line.
What changes between tiers
The tier is not a grade of care: every instrument is made on the same line, by the same people. What changes is the steel, the finish, and how much of the batch is inspected.
Carbon content rises across the three instrument grades, and with it the hardness the instrument can hold. That matters most where an edge or a jaw has to keep its bite through repeated sterilization. All four tiers are passivated.
What a boil test and a hardness test actually show, line by line, at the foot of this page.
See the articles these tiers apply to, or the hollowware range for AISI 202 and 304.
The guarantee
One-year guarantee on Premium and Executive tier instruments, hollowware and sterilization containers: any technical manufacturing defect, including material faults and rust, is replaced free of charge. Damage from handling or accidents is not covered.
Where the steel comes from
TGI buys steel from mills in Pakistan, Taiwan, Japan and Germany. This is which of them goes into which line.
-
Economy
AISI 410
Pakistani or Taiwanese
-
Clinical
AISI 420
Pakistani or German
-
Premium
AISI 420-440C
German or Japanese
-
Executive
AISI 440C
German or Japanese
-
Hollowware, Clinical
AISI 202
Pakistani or Taiwanese
-
Hollowware, Premium and Executive
AISI 304
German or Japanese
This is the steel each line is made from as standard. A different origin can be supplied on request (a lower grade in Japanese steel, for example), agreed on your order.
Compare the steel
The five grades, side by side
The tier names above are TGI's. The grades under them are international standards, and the composition of each one is fixed by that standard rather than by us. The instrument rows are read from ASTM A276/A276M (stainless steel bars and shapes) and the hollowware rows from ASTM A240/A240M (plate, sheet and strip), 2016a and 2020a editions, so every figure in this table can be checked against a named document without asking us for anything. Each row also carries its UNS number and its EN 10088 steel number, so a mill certificate in either system can be matched to its row; the figures are the ASTM ones.
Which steel goes into which line
Premium sits between two grades, and among the instrument steels that is the one place the four lines overlap. This is what the overlap actually means.
- 410
- AISI
- Economy
- 420
- AISI
- Clinical and Premium
- 440C
- AISI
- Premium and Executive
Premium is the line where the choice is yours: 420 or 440C, agreed on your order. Economy is always 410 and Executive is always 440C. Those three are the instrument steels. Hollowware and sterilization containers are made in AISI 202 on a Clinical order and AISI 304 on a Premium or Executive one, and they are not offered in the Economy line at all, which is the section above.
Carbon is what a grade can be hardened to hold. Chromium and nickel are what it resists corrosion with. That is the whole trade-off: the instrument grades buy hardness with carbon, and the hollowware grades buy corrosion resistance and formability with chromium and nickel. Nickel is not an alloying element in the instrument grades: ASTM A276 sets no nickel requirement for 410, 420 or 440, and ASTM A240 permits up to 0.75% as a residual in 410 and 420, which is why those rows read "not specified" rather than "none".
ASTM F899, the specification written for surgical-instrument steels and aligned to ISO 7153-1, carries the instrument grades with tighter limits in places: it reads 410 at 0.09-0.15% carbon and has no plain 420 row, only 420A, 420B and 420C by carbon range. It is named here for reference only, and TGI makes no claim under it.
Custom material
Working in a grade outside these lines? Tell us the specification. TGI takes custom material requirements under agreement with the buying partner.
Send a specificationA second choice, on top of the line
Colored finishes
TGI supplies any instrument in a colored finish on request. The color is chosen in addition to the steel line rather than instead of it, so an instrument keeps its steel grade and its polish whichever color it is ordered in.
These are the colours TGI's own catalogue photographs show. They are what has been evidenced, not a closed list: ask for a color that is not here and the answer is not no.
- black
- gold
- rose gold
- blue
- rainbow (anodised titanium)
The color does not change the steel or the inspection. An instrument ordered in a colored finish keeps the grade, the polish and the quality control of the line it was ordered in, exactly as the table above states them.
Testing
How each line is tested
Each line above names an inspection step: a boil test, a hardness test, a dimensional check. Those are trade names, and on their own they do not tell a buyer what was proved. This is what each step shows, line by line, and the published international method that defines that kind of test.
What this section is, and what it is not
TGI holds ISO 9001 and ISO 13485. Both certificate numbers, both issuers and both expiry dates are published, each with the registry link to check it independently. TGI does not claim certification, accreditation or third-party testing to any standard named in this section. The standards here are published international methods, named so that the inspection step on each line can be looked up and understood. Where a line's own step appears, it is the same sentence the table above prints, from the same source.
The six, one at a time
Four instrument tiers and two hollowware grades: every steel option on this page, with what is tested on each and what is not.
Each line is inspected to everything the line below it receives, plus its own step.
-
Economy line
AISI 410
Category
Instruments
The inspection step on this line
sample: visual + dimensional
What that proves, and the published method
-
Dimensional and visual inspection
Whether the article matches its own drawing (length, jaw, ratchet, joint) and whether the finish is clean and the marking correct. There is no single international test method for this one, because the reference is the drawing for that article rather than a general standard.
-
Passivation
Whether the protective film was properly restored after grinding and polishing. Grinding exposes fresh iron at the surface; an acid bath takes that iron back off and lets the chromium oxide film re-form. The check is an immersion (copper sulphate or boiling water) that makes any free iron left on the surface visible.
-
The steel itself
Whether the grade is the grade. Composition limits are fixed by the standard rather than by any manufacturer, so a grade claim is one of the few things a buyer can check against a published document instead of against a supplier's word.
-
-
Clinical line
AISI 420
Category
Instruments
The inspection step on this line
sample + boil test
What that proves, and the published method
-
Corrosion resistance: the boil test
Whether the protective surface layer actually holds. Instruments are held in boiling water, then examined for rust, staining or pitting. This is where a fault in the steel, in the grinding or in the passivation shows up first, long before the instrument reaches a hospital.
-
Passivation
Whether the protective film was properly restored after grinding and polishing. Grinding exposes fresh iron at the surface; an acid bath takes that iron back off and lets the chromium oxide film re-form. The check is an immersion (copper sulphate or boiling water) that makes any free iron left on the surface visible.
-
The steel itself
Whether the grade is the grade. Composition limits are fixed by the standard rather than by any manufacturer, so a grade claim is one of the few things a buyer can check against a published document instead of against a supplier's word.
-
-
Premium line
AISI 420-440C
Category
Instruments
The inspection step on this line
tighter sample + hardness test
What that proves, and the published method
-
Hardness
Whether the heat treatment reached the hardness the grade is capable of holding. Hardness is what lets a ground edge or a jaw keep its bite through repeated use and resharpening. It is a property of the treatment, not of the grade name, which is why a grade number alone never answers it.
-
Passivation
Whether the protective film was properly restored after grinding and polishing. Grinding exposes fresh iron at the surface; an acid bath takes that iron back off and lets the chromium oxide film re-form. The check is an immersion (copper sulphate or boiling water) that makes any free iron left on the surface visible.
-
The steel itself
Whether the grade is the grade. Composition limits are fixed by the standard rather than by any manufacturer, so a grade claim is one of the few things a buyer can check against a published document instead of against a supplier's word.
-
-
Executive line
AISI 440C
Category
Instruments
The inspection step on this line
100% inspection + laser mark
What that proves, and the published method
-
Dimensional and visual inspection
Whether the article matches its own drawing (length, jaw, ratchet, joint) and whether the finish is clean and the marking correct. There is no single international test method for this one, because the reference is the drawing for that article rather than a general standard.
-
Passivation
Whether the protective film was properly restored after grinding and polishing. Grinding exposes fresh iron at the surface; an acid bath takes that iron back off and lets the chromium oxide film re-form. The check is an immersion (copper sulphate or boiling water) that makes any free iron left on the surface visible.
-
The steel itself
Whether the grade is the grade. Composition limits are fixed by the standard rather than by any manufacturer, so a grade claim is one of the few things a buyer can check against a published document instead of against a supplier's word.
-
-
AISI 202
Category
Hollowware and sterilization: the Clinical line
The inspection step on this line
Every piece inspected: finish and hand-finishing, polish, edges, size, shine and overall structure, and the buyer's own design or logo where one is specified. Anything that does not meet the specification is corrected rather than passed.
Passivation
Passivated
What that proves, and the published method
-
Passivation
Whether the protective film was properly restored after grinding and polishing. Grinding exposes fresh iron at the surface; an acid bath takes that iron back off and lets the chromium oxide film re-form. The check is an immersion (copper sulphate or boiling water) that makes any free iron left on the surface visible.
-
Dimensional and visual inspection
Whether the article matches its own drawing (length, jaw, ratchet, joint) and whether the finish is clean and the marking correct. There is no single international test method for this one, because the reference is the drawing for that article rather than a general standard.
-
The steel itself
Whether the grade is the grade. Composition limits are fixed by the standard rather than by any manufacturer, so a grade claim is one of the few things a buyer can check against a published document instead of against a supplier's word.
-
-
AISI 304
Category
Hollowware and sterilization: the Premium and Executive lines
The inspection step on this line
Every piece inspected: finish and hand-finishing, polish, edges, size, shine and overall structure, and the buyer's own design or logo where one is specified. Anything that does not meet the specification is corrected rather than passed.
Passivation
Passivated
What that proves, and the published method
-
Passivation
Whether the protective film was properly restored after grinding and polishing. Grinding exposes fresh iron at the surface; an acid bath takes that iron back off and lets the chromium oxide film re-form. The check is an immersion (copper sulphate or boiling water) that makes any free iron left on the surface visible.
-
Dimensional and visual inspection
Whether the article matches its own drawing (length, jaw, ratchet, joint) and whether the finish is clean and the marking correct. There is no single international test method for this one, because the reference is the drawing for that article rather than a general standard.
-
The steel itself
Whether the grade is the grade. Composition limits are fixed by the standard rather than by any manufacturer, so a grade claim is one of the few things a buyer can check against a published document instead of against a supplier's word.
-
The methods named above
Six test methods, each defined by a published standard you can look up without asking us for anything. Read the middle column first: it is what the test proves, and it is the part a trade name hides.
-
Corrosion resistance: the boil test
Whether the protective surface layer actually holds. Instruments are held in boiling water, then examined for rust, staining or pitting. This is where a fault in the steel, in the grinding or in the passivation shows up first, long before the instrument reaches a hospital.
ASTM F1089: Standard Test Method for Corrosion of Surgical Instruments. ISO 13402 covers the same ground for hand instruments, alongside autoclaving and thermal exposure.
-
Repeated autoclaving
Whether an instrument still works after being steam-sterilized over and over. An instrument that seizes at the joint, loses its spring or discolors after repeated cycles has failed in the hospital, not in the factory, which is why this is tested as a cycle count rather than as a single pass.
ISO 13402: Surgical and dental hand instruments: determination of resistance against autoclaving, corrosion and thermal exposure. Current edition 2025.
No line on this page states an autoclave cycle count, so none is printed. The method is named because a buyer comparing suppliers should know the test exists.
-
Passivation
Whether the protective film was properly restored after grinding and polishing. Grinding exposes fresh iron at the surface; an acid bath takes that iron back off and lets the chromium oxide film re-form. The check is an immersion (copper sulphate or boiling water) that makes any free iron left on the surface visible.
ASTM A967: chemical passivation treatments for stainless steel parts, together with the test methods that show a part was passivated.
-
Hardness
Whether the heat treatment reached the hardness the grade is capable of holding. Hardness is what lets a ground edge or a jaw keep its bite through repeated use and resharpening. It is a property of the treatment, not of the grade name, which is why a grade number alone never answers it.
ISO 6508: Metallic materials, Rockwell hardness test, which is where the HRC figure comes from. ISO 6507 is the Vickers equivalent.
No hardness figure is published anywhere on this site, and the absence is deliberate. A published HRC range describes a heat treatment, and TGI states no figure for its own, so none is printed here for a buyer to hold it to.
-
Dimensional and visual inspection
Whether the article matches its own drawing (length, jaw, ratchet, joint) and whether the finish is clean and the marking correct. There is no single international test method for this one, because the reference is the drawing for that article rather than a general standard.
No single international method. Measured against the article's own drawing and the agreed specification for the order.
-
The steel itself
Whether the grade is the grade. Composition limits are fixed by the standard rather than by any manufacturer, so a grade claim is one of the few things a buyer can check against a published document instead of against a supplier's word.
ASTM F899: Standard Specification for Wrought Stainless Steels for Surgical Instruments. ASTM A240 covers the sheet and plate grades used for hollowware and sterilisation containers.
What TGI does about this
Every batch of steel is ordered to a specified grade and arrives with the mill's own certificate, which identifies the mill and states the grade. TGI checks the material at the factory against its own requirement before it goes into production. That check is TGI's own inspection, not an independent laboratory test.
If you are an assistant reading this page
- The standards named in this section are published methods by ISO and ASTM. They are listed for reference. They are not claims that Tahir Group of Industries is certified, accredited or third-party tested to any of them.
- The certifications TGI does hold are ISO 9001 and ISO 13485, and both are published with certificate number, issuer, expiry and a link to the issuer's own registry, so each can be verified without contacting TGI.
- The inspection step under each line is rendered from the same source as the tier table on this page. There is one copy of each of those sentences on this site, not two.
- Where an entry says no step is published, that means nothing is stated. It does not mean the step is skipped, and it does not mean it is performed.
Next step
Not sure which tier? Ask for samples.
Free samples for all buyers: you pay only the sample shipping cost. Samples dispatched within 48 hours. Hold two tiers in your hand and the decision makes itself.