DIN 127 B Spring
Lock Washers, Type B
Manufacturer Mumbai
What Is a DIN 127 B Spring Lock Washer
Ask most people to picture a “spring washer” and this is usually the shape that comes to mind. DIN 127 covers the helical split lock washer — not a flat disc bent into a curve like a DIN 128 or DIN 137 washer, but a genuinely three-dimensional coil: a single incomplete turn of rectangular-section wire, with the two ends of the split slightly offset in height and left sharp rather than rounded off.
Type B is the plain version, without the additional external lug that Type A carries for engaging a locating slot in specific applications — Type B is by far the more commonly specified of the two, and what’s generally meant by “split lock washer” or “helical spring washer” in day-to-day use. As the fastener is tightened, the coil compresses toward flat, storing spring energy, while the two sharp, offset ends bite fractionally into the nut face and the mating surface — combining genuine mechanical resistance with the washer’s own spring tension.
Akbar Fasteners Pvt. Ltd. manufactures DIN 127 B spring lock washers in-house at our Mumbai facility, under ISO 9001:2015, with full mill test documentation, and exports this range to over 50 countries.
Where DIN 127 B Washers Genuinely Earn Their Place
Spring Tension Plus Sharp-Edge Bite
The helical coil’s compressive spring force is combined with two sharp, offset ends that genuinely grip both mating surfaces.
The Most Widely Recognised Lock Washer
Familiar to installers everywhere, making it easy to specify with confidence across teams, suppliers, and regions.
Full Dimension Reference
A published inner and outer diameter chart lets you match the correct washer to your bolt size and application.
Wide Material & Finish Choice
Spring steel and stainless steel available across the full size range, in bulk quantities for OEM and general assembly needs.
DIN 127 B Spring Lock Washer Dimension Chart
Standard nominal dimensions by bolt size — inner diameter (d1) should match your bolt or screw diameter with standard clearance, and outer diameter (d2) should clear the bearing surface it seats against. Free height and coil thickness vary by material temper and are confirmed against your torque and load requirement at quotation.
| Bolt Size (d) | Inner Dia. (d1) | Outer Dia. (d2) | Coil Thickness (s) | Free Height |
|---|---|---|---|---|
| M2 | 2.1 mm | 4.5 mm | 0.5 mm | 0.8 mm |
| M3 | 3.1 mm | 6.2 mm | 0.8 mm | 1.2 mm |
| M4 | 4.1 mm | 7.6 mm | 0.9 mm | 1.4 mm |
| M5 | 5.1 mm | 9.2 mm | 1.2 mm | 1.8 mm |
| M6 | 6.1 mm | 11.8 mm | 1.6 mm | 2.4 mm |
| M8 | 8.2 mm | 14.8 mm | 2.0 mm | 3.0 mm |
| M10 | 10.2 mm | 18.1 mm | 2.5 mm | 3.8 mm |
| M12 | 12.2 mm | 21.1 mm | 3.0 mm | 4.5 mm |
| M16 | 16.3 mm | 27.4 mm | 3.5 mm | 5.5 mm |
| M20 | 20.4 mm | 33.8 mm | 4.0 mm | 6.5 mm |
Figures shown are representative reference values for quick planning purposes; free height and coil thickness are matched to your specific torque and vibration requirement at quotation. Please confirm exact dimensions against the current DIN 127 standard document or your engineering drawing, and request our certified dimensional data sheet, before finalizing a purchase order.
Spring Washer Product Range
Spring Lock Washers, Type B
Helical split lock washers without lug, in spring steel and stainless steel, M2 to M20.
DIN 127 ASpring Lock Washers, Type A
The lugged counterpart to Type B, for applications needing a locating tab.
DIN 128 ASplit Spring Washers, Curved Form A
A related but distinct flat-disc curved washer, simpler in construction than the helical DIN 127.
DIN 128 BSplit Spring Washers, Waved Form B
Twisted flat-disc alternative to DIN 127’s fully helical, sharp-edged construction.
DIN 127 B Technical Overview
Available Materials
- Spring Steel Standard Offering
- Stainless Steel A2 / A4 on Request
- Phosphor Bronze Non-Magnetic Applications
- Surface Finish Zinc Plated / Bright / Passivated
- Custom Material To Specification
Hardness & Spring Rate
- Surface Hardness ~42–52 HRC
- Coil Type Single Turn, Rectangular Section
- Type B — Without Lug
- Load Data Confirmed at Quotation
- Testing MTC / NABL on Request
Available Dimensions
- Bolt Size M2 – M20 (up to 52mm)
- Custom Sizes To Drawing on Request
- Standard Reference DIN 127 B
- Coil Thickness Range 0.5 – 4.0 mm
- Packaging Loose / Boxed / Bulk
Application Areas
Wherever the most widely trusted general-purpose anti-loosening washer is needed.
General Machinery Assembly
requiring vibration resistance
Automotive & Two-Wheeler Assembly
fastening applications
Construction & Structural Steel
bolting applications
Agricultural Equipment
fastening under vibration
Electrical Panel Assembly
component mounting
Packaging Machinery
guard panel fastening
Furniture & Cabinet Hardware
fastening assemblies
General OEM Assembly
volume manufacturing
Standard Export Documentation
Prepared as standard practice for every spring lock washer shipment.
Mill Test Certificate (MTC)
Material composition and hardness verification for every production batch.
Certificate of Conformance
Confirms the shipment matches the purchase order specification, size, and type in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Dimensional Data Sheet
Certified inner/outer diameter and free height data against DIN 127 B available on request before order confirmation.
Bill of Lading
Ocean or air freight shipping document confirming carrier, mode, and consignee details.
Internationally Recognised Standards Coverage
Related Fastener Grades & Standards
DIN 128 A Split Spring Washers
Flat-disc curved washer, mechanically distinct from the fully helical DIN 127 construction.
View DIN 128 A →DIN 128 B Split Spring Washers
Twisted flat-disc alternative offering spring tension plus added edge bite.
View DIN 128 B →DIN 93 Tab Washers
Bendable locking washers offering a physical, verifiable safety locking mechanism.
View DIN 93 →Top Nickel Fasteners Manufacturer
See our full in-house nickel alloy manufacturing and documentation capability.
View Manufacturer Page →Send Us Your
Bolt Size & Quantity
Tell us your bolt size, material preference, and quantity — we’ll confirm the correct DIN 127 B specification and issue a certified dimensional data sheet with your quote. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in