Why Buyers Trust Ganpat Industrial For ASTM A193 Grade B7M Washers?
NACE MR0175 Compliant
Hardness capped at 235 HBW on every washer batch for sour-service readiness.
Genuine 4140/4142 Chemistry
Each heat is lab-checked against Cr-Mo alloy limits before forging starts.
Flat, Spring & Conical Types
Nine washer styles rolled and pressed together to match your stud programme.
Batch-Wise Hardness Log
Brinell reports issued heat-by-heat so every dispatch stays audit ready.
Ready Stock, Fast Dispatch
High-turnover sizes packed and moving within days of order confirmation.
ASTM A193 Grade B7M Washers Snapshot
- 1Product Family: Flat, Spring, Conical, Split, Star, Slot & Spherical Washers
- 2Size Coverage: M6 to M100 | 1/4″ to 4″ nominal bolt fit
- 3Governing Standard: ASTM A193 / A193M, ASME B18.22.1, ASTM F436M
- 4Coating Options: Black Oxide, Bright Zinc, Hot-Dip Galvanized, PTFE
- 5Common Marking: B7M, A193 B7M, 4140M, WNr 1.7225 Mod.
- 6Service Use: Sour Gas, Refinery, Offshore & High-Pressure Flanges
Or call our Mumbai office: +91 22 6743 7134 • Sour-service washers dispatched with hardness proof
Every alloy steel washer leaving our press shop uses certified chromium-molybdenum bar. Each washer is tempered above 621°C, staying below 235 HBW. Buyers seeking ASTM A193 Grade B7M Washers Supplier in India trust us. Our matching washers use identical heats as our B7M stud line. This keeps hardness, chemistry, and torque behaviour aligned across flange joints. Flat, spring, conical, and star patterns meet diverse assembly requirements. Each washer sits flush beneath B7M nuts during demanding applications. They suit refinery, offshore, and high-pressure piping assemblies requiring dependable performance.
Mumbai · Alloy Steel B7M Fastener Accessory Exporter
ASTM A193 Grade B7M Washers
Ganpat Industrial forges and presses Alloy Steel B7M Washers / A193 AS B7M Conical Washer / DIN 1.7225 B7M Flat Washer ranges for fabricators who cannot compromise on sub-235 HBW hardness in sour crude, refinery and offshore flange joints across India, the GCC and Southeast Asia.
- ✓ISO 9001:2015
- ✓NACE MR0175 / ISO 15156
- ✓PED 2014/68/EU
- ✓Mill Test Certificate 3.1
- ✓Third-Party Inspection Approved
Leading ASTM A193 Grade B7M Washers Manufacturer in India Offering Custom Sizes At Factory-Direct Price
Specification Of ASTM A193 Grade B7M Washers
B7M Washer Size Range
- Bore: M6 – M100 / 1/4″ – 4″
- Outside Diameter: 13mm – 220mm
- Thickness: 1.6mm – 12mm
- Standard & drawing-based sizes
B7M Star Washer Standard
- ASTM A193 / A193M
- ASME B18.22.1 (plain washers)
- ASTM F436M (hardened)
- DIN 125 / DIN 6796
B7M Washer Route
- Hot Forging / Blanking
- Quenching & Tempering
- Piercing & Facing
- Precision Grinding
B7M Flat Washers Finish
- Black Oxide (Mill Finish)
- Bright Zinc Plated
- Hot-Dip Galvanized
- PTFE / Xylan Coated
B7M Sealing Washer Grade Material
- 4140 / 4142 Cr-Mo Steel
- DIN 1.7225 Modified
- Through-Hardened Structure
- Sour-Service Tempered
B7M Spring Washer Testing Coverage
- Brinell Hardness Test
- PMI Testing
- Dimensional Check
- Third-Party Inspection
Sizes Of ASTM A193 B7M Alloy Steel Split Washer
Contact ASTM A193 Grade B7M Washers Supplier in India For Custom Sizes.
Bore Diameter
M6 – M100
1/4″ to 4″ nominal fit
Outside Diameter
13mm – 220mm
Standard & wide-body options
Thickness Range
1.6mm – 12mm
Flat, spring & conical profiles
Tolerance Class
ISO 2768 – m
Medium tolerance, drawing on request
Dimension Of ASTM A193 B7M Washers
| D | d1 | d2 | h |
|---|---|---|---|
| M1 | 1.1000 | 3.0000 | 0.3000 |
| M1.2 | 1.3000 | 3.5000 | 0.3000 |
| M1.4 | 1.5000 | 4.0000 | 0.3000 |
| M1.6 | 1.7000 | 4.0000 | 0.3000 |
| M1.7 | 1.8000 | 4.5000 | 0.3000 |
| M2 | 2.2000 | 5.0000 | 0.3000 |
| M2.3 | 2.5000 | 6.0000 | 0.5000 |
| M3 | 3.2000 | 7.0000 | 0.5000 |
| M3.5 | 3.7000 | 8.0000 | 0.5000 |
| M4 | 4.3000 | 9.0000 | 0.8000 |
| M5 | 5.3000 | 10.0000 | 1.0000 |
| M6 | 6.4000 | 12.0000 | 1.6000 |
| M7 | 7.4000 | 14.0000 | 1.6000 |
| M8 | 8.4000 | 16.0000 | 1.6000 |
| M10 | 10.5000 | 20.0000 | 2.0000 |
| M12 | 13.0000 | 24.0000 | 2.5000 |
| M14 | 15.0000 | 28.0000 | 2.5000 |
| M16 | 17.0000 | 30.0000 | 3.0000 |
| M18 | 19.0000 | 34.0000 | 3.0000 |
| M20 | 21.0000 | 37.0000 | 3.0000 |
Manufacturer of Alloy Steel B7M Slot Washers, Alloy Steel Flat Washer, Alloy Steel B7M Slot Spring Washer, Alloy B7M Lock Washers in India
Types Of Alloy Steel B7M Washers
As an active ASTM A193 Grade B7M Washers Supplier in India, we stock all washer used across sour-service bolting programmes.
A193 AS B7M Conical Washer
DIN 6796
Alloy Steel B7M Slot Washers
Custom Drawing
Alloy Steel B7M Slot Spring Washer
DIN 128
ASTM A193 Alloy Steel Machine Washer
ASME B18.22.1
B7M Alloy Steel Star Washers
DIN 6797
B7M AS Spherical Washer
DIN 6319
Alloy Steel Flat Washer
ASTM F436M
ASTM A193 B7M Alloy Steel Split Washer
DIN 127
Documentation & Test Certificates Offered With B7M Flat Washers
Mill Test Certificate 3.1
Chemistry, hardness & tensile results traced to heat number
Every Order
PMI Test Report
Positive Material Identification confirming Cr & Mo content
On Request
Brinell Hardness Report
Confirms compliance with the 235 HBW NACE MR0175 limit
On Request
Certificate Of Origin
For customs clearance & import duty processing
Export Orders
Packing List & Invoice
PO-matched, HSN & GST breakup included
Every Order
Need A Custom B7M Washer Drawing Matched?Share your OD, bore & thickness list – get a factory-price quote within 24 hours.
Equivalent Grades Of B7M Alloy Steel Washers
ASTM / UNS
- ASTM A193 Grade B7M
- ASTM A320 Grade L7M
- UNS G41400 (4140 base)
- AISI 4140 / 4142
DIN / WNr
- WNr 1.7225 (Modified)
- 42CrMo4 Base Chemistry
- DIN 6796 / DIN 125 Form
- EN 10269 Reference
JIS / Other
- JIS SCM440 Proximate
- IS 1367 (Indian Fastener Ref.)
- Often searched as UNS S41400
HSN Code For ASTM A193 Grade B7M Washers
HSN Code – Flat Washers
7318.22
Other washers of iron or steel, not threaded
HSN Code – Spring/Lock Washers
7318.21
Spring washers & other lock washers of steel
GST Slab
18%
Applicable on domestic supply within India
Export Incentive
RoDTEP Eligible
Duty remission on qualifying export shipments
Confused Between B7M And B7 Washer Hardness Limits?Send your service condition – we recommend the correct grade.
Chemical Composition Of Alloy Steel B7M Washers
CarbonC
0.38-0.48%
ManganeseMn
0.75-1.00%
ChromiumCr
0.80-1.10%
MolybdenumMo
0.15-0.25%
SiliconSi
0.15-0.35%
PhosphorusP
≤ 0.035%
SulphurS
≤ 0.040%
Base chemistry aligns with AISI 4140 / 4142 Cr-Mo bar stock, heat-verified before forging into washer blanks.
Mechanical Properties Of ASTM A193 B7M Washers
Tensile Strength
689-931 MPa
100-135 ksi
Yield Strength (0.2%)
≥ 552 MPa
80 ksi Min
Elongation (2″)
≥ 16%
Ductility
Hardness (Max)
≤ 235 HBW
Sour-Service Cap
Need A Certified Hardness & Tensile Report?Send size, quantity & standard for a free document review.
B7M Washers NACE MR0175 Sour Service Compliance
The letter “M” in B7M exists purely for this reason – a softer, crack-resistant washer for H2S-bearing lines.
Tempered Above 621°C
High-temper cycle lowers strength on purpose to resist sulfide stress cracking
235 HBW Hardness Ceiling
Every lot is Brinell-checked so no washer crosses the sour-service limit
ISO 15156 Recognised
Chemistry & hardness combination accepted for global oilfield contracts
B7M Washer Vs B7 Washer – Which To Choose ?
B7M Washer
- Hardness capped at 235 HBW
- Tempered above 621°C for softness
- Required for sour / H2S service
- NACE MR0175 mandatory selection
Standard B7 Washer
- Higher permissible hardness, up to 321 HBW
- Tempered at a lower minimum temperature
- Suited to sweet, non-sour service
- Not accepted where H2S exposure exists
Weekly Delivery Of ASTM A193 Grade B7M Washers In These Countries
| Export to | Continent | Shipping Time |
|---|---|---|
Mexico |
North America | 45 Days |
South Africa |
Africa | 25-30 Days |
Kenya |
Africa | 19 Days |
Oman |
Asia | 5 Days |
Testing Methods For B7M Alloy Steel Star Washers
Every ASTM A193 Grade B7M Washers Manufacturer in India worth ordering from should be able to show you these five checks on paper.
PMI Testing
Positive Material Identification on every heat
Brinell Hardness Test
Confirms the 235 HBW sour-service ceiling per lot
Dimensional Inspection
Bore, OD & thickness checked against drawing
Application Of ASTM A193 B7M Washers
Reach out to an ASTM A193 Grade B7M Washers Supplier in India who already ships into these sectors every month.
Off-Shore Oil Drilling Companies
Power Generation
Petrochemicals
Pipeline Valve & Fitting Joints
Gas Processing
Pharmaceutical Equipment
Sea Water Equipment
Chemical Equipment
Manufacturing Process Of Alloy B7M Lock Washers
Bar Selection & Heat Check
4140/4142 bar stock verified against the B7M heat certificate first
Hot Forging / Blanking
Bar is forged or blanked into the rough washer disc profile
Quench & High Temper
Oil quenched then tempered above 621°C to hold hardness under 235 HBW
Piercing & Facing
Bore is pierced and both faces machined flat and parallel
Grinding & Hardness Check
Final grinding, Brinell check and PMI verification before dispatch
Monthly Delivery Of ASTM A193 Grade B7M Washers In These Countries
| Export to | Continent | Shipping Time |
|---|---|---|
Indonesia |
Asia | 9 Days |
Philippines |
Asia | 14 Days |
Spain |
Europe | 30 Days |
Germany |
Europe | 20 Days |
Surface Coating Options For Alloy Steel B7M Washers
Black Oxide Finish
Economical mill finish with light corrosion cover for indoor lines
Bright Zinc Plated
Electroplated zinc layer for moderate outdoor corrosion resistance
Hot-Dip Galvanized
Thick zinc coating built for coastal & offshore atmospheric exposure
PTFE / Xylan Coated
Low-friction dry-film layer that steadies torque-tension on assembly
Phosphate & Oil
Paint-base phosphate layer with oil seal for short-term storage protection
Need A Coating Recommendation For Your Site?Tell us the exposure & we will suggest the right finish.
Installation Guideline For ASTM A193 B7M Washers
Match The Washer To The Stud Grade
Never pair a B7M washer with hardened B16 or B7 studs on sour duty
Step 1
Seat The Washer Flat Against The Flange
Chamfered side generally faces outward toward the nut face
Step 2
Apply A Cross-Bolt Tightening Pattern
Reduces uneven washer loading and flange face distortion
Step 3
Torque To The Stud Manufacturer’s Chart
Do not exceed torque values set for the softer B7M chemistry
Step 4
Re-Check After First Thermal Cycle
Retorque once the line has been through one heat-up and cool-down
Step 5
Packaging & Export Standard
VCI Poly Bagging
Vapour corrosion inhibitor bags for small washer counts
Size-Wise Carton Boxing
Cartons labelled with size, grade & heat number
Wooden Pallet / Crate
Export-fumigated pallets for bulk container loading
Container Stuffing & Photos
Loading photos shared before the container is sealed
Price Factors For B7M Washers
Share these five inputs with our team for accurate, factory-direct costing on your enquiry.
Frequently Asked Questions
Why does B7M have a lower hardness than B7?
The higher temper temperature softens the steel on purpose so it resists sulfide stress cracking in sour, H2S-bearing service.
What is the HSN code for alloy steel washers?
Flat washers generally fall under HSN 7318.22 while spring and lock-type washers fall under HSN 7318.21.
Can B7M washers be used with B7 studs?
It is not recommended in sour service, since mixing hardness classes defeats the NACE MR0175 intent of the joint.
Do B7M washers need a specific coating?
No mandatory coating is specified; black oxide, zinc or PTFE are chosen based on the site’s corrosion exposure.
What is commonly searched as UNS S41400 washer actually?
That UNS number belongs to 410-type stainless; B7M washers are correctly referenced under UNS G41400 (4140 base steel).
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6 Reasons to choose Ganpat Industrial Corporation
- Distributor of Heat Exchanger parts and Alloys for High Temperature applications.
- Stockholder and importer of Ferrous and non ferrous metals.
- Wide stock of prime quality austenitic and Ferritic Stainless Steel for Extreme pressure environment.
- Marine grade steel at lowest price in Mumbai.
- Compare Price per KG in India and China.
- Offer Resale price to local suppliers, traders and wholesalers in UAE, Saudi Arabia, Egypt, and USA