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angled view of a silver 3/8" spark plug socket showing square drive recess and knurled bandside view of silver deep-well spark plug socket with brass-colored inner collar and six-point interiortop view inside a spark plug socket showing six-point interior and brass-colored retention ring

3/8-Inch Drive Spark Plug Socket, 21mm, 6-Point, 65mm Deep Well

Professional-grade 21mm spark plug socket with magnetic insert and deep-well design for reliable engine maintenance.

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Description

3/8-Inch Drive Spark Plug Socket, 21mm, 6-Point, 65mm Deep Well

Brief Overview

This 21mm spark plug socket is engineered for precision removal and installation of spark plugs in modern automotive engines. The deep-well design accommodates extended plug bodies and boot clearance, while the integrated brass magnetic insert secures the plug during operation—eliminating dropped fasteners and streamlining service calls. Available in 16mm and 18mm sizes as well, this socket family ensures your shop covers the full spectrum of spark plug applications. For shops seeking magnetic spark plug socket solutions or comprehensive spark plug socket sets, we offer complementary options that round out your pneumatic toolkit.

Key Features

  • 6-Point Interior Geometry: Provides secure, positive grip on spark plug hexagons without cam-out risk
  • Brass Magnetic Insert: Holds spark plugs firmly in place during extraction and installation; prevents loss in tight engine bays
  • Deep-Well Configuration: 65mm length accommodates modern long-reach spark plugs and coil-pack assemblies
  • Knurled Grip Band: Textured section near the hex drive improves handling and reduces grip fatigue during extended use
  • 3/8-Inch Drive Compatibility: Integrates seamlessly with standard ratchets, impact drivers, and socket extensions
  • Durable Satin Nickel Finish: Corrosion-resistant coating maintains appearance and function across seasons
  • Matte Silver Exterior: Professional appearance suitable for retail display or shop use

Business Advantages for Resellers

  • High-Velocity SKU: Spark plug service is seasonal and recurring—customers return regularly for replacements
  • Bulk Order Economics: These sockets are lightweight, compact for shipping, and stackable for efficient warehouse management
  • Margin-Friendly Positioning: Position as an essential accessory upsell alongside ratchets, extensions, and socket sets
  • Professional-Grade Quality: Magnetic insert and precision manufacturing justify confident resale to independent shops and fleet maintenance providers
  • Size Variety: Stock 16mm, 18mm, and 21mm to capture the full vehicle range (domestic and import) and build customer loyalty

Technical Specifications

Specification Value
Drive Size 3/8 inch
Socket Size (Metric) 21mm
Interior Profile 6-point
Overall Length 65mm
Outer Diameter (D1) 28mm
Bore Diameter (D2) 21.5mm
Material Steel with brass magnetic insert
Finish Satin nickel
Deep-Well Design Yes
Magnetic Retention Integrated brass insert

Why This Socket Matters for Your Customers

Modern spark plug service demands precision and reliability. The 6-point design minimizes rounding—a critical advantage when working with seized or corroded plugs in tight head configurations. The magnetic insert is not cosmetic; it prevents the plug from dropping into the engine bay during extraction, saving technicians time and frustration.

The 65mm depth is specifically calibrated for long-reach plugs found in V6 and V8 engines, making this socket indispensable for general automotive repair and fleet maintenance.

Ready to stock professional spark plug solutions? Order bulk quantities today and establish your shop as a trusted supplier of precision automotive tools.