Home » Metric Tapered Socket Pipe Plugs (DIN 906) - Marine Stainless Steel (A4)

Metric Tapered Socket Pipe Plugs (DIN 906) - Marine Stainless Steel (A4)

Metric Tapered Socket Pipe Plugs - DIN 906 | Marine Stainless Steel A4 (SUS316) | A4-70 | Pickled & Passivated

FULLERKREG DIN 906 metric tapered hexagon socket screw plugs in A4 marine-grade stainless steel (SUS316 / EN 1.4401), A4-70 strength grade, pickled & passivated surface finish. The premium choice for self-sealing port closures in saltwater, chemical, and aggressive industrial environments. DIN 906 conical thread creates a self-sealing interference fit - no additional sealing washer required. Internal hexagon socket drive allows flush or recessed installation.

Product Overview

  • Standard: DIN 906 (Tapered Hexagon Socket Screw Plugs)
  • Thread Type: Metric conical (tapered) thread - self-sealing by thread interference
  • Material: A4 Marine Stainless Steel (SUS316 / EN 1.4401)
  • Strength Grade: A4-70 (ISO 3506-1)
  • Surface Treatment: Pickled & Passivated
  • Drive: Internal hexagon socket (Allen / hex key)
  • Size Range: M6x1 to M48x1.5
  • Brand: FULLERKREG

Dimensions - DIN 906 Metric Tapered Socket Plugs

All dimensions in mm. Per DIN 906 standard. d = nominal thread diameter, h = plug height, k = socket depth. Weight in kg/100pcs.

Size (d x pitch) d (mm) h (mm) k (mm) S/AF (mm) Weight (kg/100pcs)
M6x1 6 6 3 4 0.02
M8x1 8 8 4 5 0.04
M10x1 10 10 5 6 0.08
M12x1.5 12 10 6 8 0.11
M14x1.5 14 10 7 8 0.15
M16x1.5 16 10 8 10 0.19
M18x1.5 18 10 8 10 0.24
M20x1.5 20 10 10 12 0.30
M22x1.5 22 12 10 12 0.43
M24x1.5 24 12 10 14 0.51
M26x1.5 26 12 10 14 0.60
M27x2 27 12 12 17 0.66
M28x1.5 28 12 12 17 0.73
M30x1.5 30 15 12 17 1.00
M33x2 33 15 14 19 1.30
M36x1.5 36 15 14 19 1.52
M38x1.5 38 18 17 22 2.10
M42x1.5 42 18 17 22 2.60
M45x1.5 45 18 17 22 3.00
M48x1.5 48 20 19 24 3.58

S/AF = internal hex socket size (Allen key size). Dimensions per DIN 906 standard.

Material & Mechanical Properties

  • Material: A4 / AISI 316 / SUS316 / EN 1.4401 - Austenitic stainless steel with molybdenum
  • Molybdenum Content: 2-3% Mo - key differentiator providing superior pitting and crevice corrosion resistance vs A2
  • Strength Class: A4-70 per ISO 3506-1
  • Tensile Strength: 700 N/mm2 min (101,500 PSI)
  • Proof Load Stress: 450 N/mm2 min
  • Nut Load Capacity: 700 N/mm2 min
  • Hardness: HV 220 max
  • Surface: Pickled & Passivated - removes free iron, maximises chromium oxide passive layer
  • Generally non-magnetic in annealed condition

Surface Treatment: Pickled & Passivated

  • Pickling: Acid treatment removes heat tint, scale, and free iron contamination from manufacturing
  • Passivation: Rebuilds dense chromium oxide (Cr2O3) passive film for maximum corrosion protection
  • Result: Bright silver-white surface with maximum corrosion resistance
  • No dimensional change - thread tolerances fully maintained
  • Per ASTM A967 / ISO 16048 passivation requirements

Key Features

  • Marine-grade corrosion resistance: 2-3% molybdenum in SUS316 dramatically improves resistance to chloride pitting - essential for saltwater, coastal, and offshore environments
  • Self-sealing conical thread: Tapered metric thread creates interference seal on tightening - no sealing washer or PTFE tape required in most applications
  • Internal hex socket drive: Allen key installation allows flush or below-surface fitting - ideal where external hex access is restricted
  • Compact low-profile design: Minimal protrusion above mating surface - suitable for space-constrained installations
  • A4-70 strength: High strength combined with maximum corrosion resistance for demanding environments
  • Chemical resistance: Resistant to many acids, alkalis, chlorides, and industrial chemicals
  • Wide size range: M6 to M48 from stock

A4 (SUS316) vs A2 (SUS304) - Why Choose Marine Grade?

Property A2 (SUS304) A4 (SUS316) - This Product
Base Alloy 18% Cr, 8% Ni 16% Cr, 10% Ni, 2-3% Mo
Molybdenum None 2-3% (pitting resistance)
Saltwater Resistance Moderate Excellent
Chloride Resistance Limited Superior
Chemical Resistance Good Very Good
Strength Grade A2-70 A4-70
Best For General industrial Marine, chemical, harsh environments

DIN 906 vs DIN 910 - Key Differences

Property DIN 906 (This Product) DIN 910
Thread Type Conical (tapered) metric Cylindrical (parallel) metric
Sealing Method Thread interference - self-sealing Face seal via collar
Drive Internal hex socket (Allen key) External hexagon head
Profile Low profile / flush Raised hex head with collar
Sealing Washer Not required Recommended for pressure sealing
Access Required Socket access only Spanner / wrench access

Typical Applications

  • Marine and offshore equipment - hull fittings, seawater systems, deck hardware
  • Shipbuilding and boat manufacturing
  • Coastal and harbour infrastructure
  • Chemical and petrochemical processing pipelines
  • Pharmaceutical and food processing (CIP systems)
  • Hydraulic cylinder and manifold port closures in corrosive environments
  • Desalination plants and water treatment facilities
  • Swimming pool and spa equipment
  • Machine tool coolant systems with aggressive coolants
  • OEM production line fastener supply

Standards & Compliance

  • DIN 906 - Tapered Hexagon Socket Screw Plugs with Metric Thread
  • ISO 3506-1 - Mechanical properties of corrosion-resistant stainless steel fasteners
  • DIN EN ISO 3506 - Steel groups and strength classes for stainless fasteners
  • ASTM A967 / ISO 16048 - Passivation of stainless steel
  • RoHS / REACH - Compliant
  • Mill Test Certificates (EN 10204 3.1) available on request

Ordering & Packaging

  • Standard bulk packaging: per 100 pcs or per 1000 pcs
  • Custom quantities for OEM and production orders
  • Labelled with size, material grade (A4-70), surface treatment, and DIN 906
  • Most sizes available from stock - fast dispatch
  • MTC / EN 10204 3.1 certificates available on request

FAQ

Q: What makes A4 better than A2 for marine applications?
A: A4 (SUS316) contains 2-3% molybdenum which dramatically improves resistance to chloride pitting and crevice corrosion - the primary failure mode in saltwater environments. A2 (SUS304) lacks molybdenum and is not recommended for prolonged saltwater exposure.

Q: Does DIN 906 require a sealing washer?
A: No. The conical (tapered) metric thread creates a self-sealing interference fit when tightened to the correct torque. For additional security in high-pressure or vibration applications, anaerobic thread sealant can be applied.

Q: What Allen key size do I need?
A: The internal hex socket size (S/AF) varies by thread size - see the dimensions table above. For example, M12x1.5 uses an 8mm hex key, M20x1.5 uses a 12mm hex key.

Q: What is the difference between DIN 906 and DIN 908?
A: DIN 906 has a tapered (conical) thread that self-seals by interference. DIN 908 has a cylindrical thread with a collar and requires a sealing washer. DIN 906 is driven by an internal hex socket; DIN 908 by an external hex head.

Q: Are Mill Test Certificates available?
A: Yes. FULLERKREG provides EN 10204 3.1 material certificates for all A4 stainless steel fasteners upon request.

Q: Is A4 stainless suitable for high-temperature applications?
A: A4 (SUS316) performs well up to approximately 870 degrees C in intermittent service. For sustained high-temperature applications above 300 degrees C, please consult our technical team.

All FULLERKREG DIN 906 marine stainless steel tapered socket pipe plugs are manufactured to DIN and ISO standards. Contact FULLERKREG for bulk pricing, OEM supply, or technical support.

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