Draper Expert Metric Socket Set, 1/4", 3/8" and 1/2" Sq. Dr. (149 Piece)

The Professional Three-Drive System Built for Modern Automotive Work

The Draper Expert STK149N/SG 149-Piece HI-TORQ® Metric Socket Set is a flagship professional toolkit that covers every drive size, socket type, and fastener format encountered in contemporary automotive servicing, engineering maintenance, and trade work — including the specialist tool types that most comprehensive sets overlook. With E-sockets on all three drive platforms, tamperproof Torx bits alongside standard Torx, large-format 1/2" drive TX-STAR® bits, deep sockets across all three drive sizes, and a fully equipped accessory suite on every platform, the STK149N/SG is engineered specifically for the demands of modern vehicle maintenance where security fasteners, E-type external Torx sockets, and tamper-resistant fixings are no longer occasional encounters but everyday requirements.

Every socket across all three drive platforms is manufactured from chrome vanadium steel, hardened and tempered for long-term Expert-series durability, finished with a micro satin chrome plate for corrosion resistance and low-glare size legibility, and fitted with a knurled ring for positive, confident one-handed grip. Three 72-tooth reversible ratchets with soft grip handles and quick-release buttons — one per drive size — ensure the correct ratchet is always paired with the platform in use. The complete set is supplied in a tough plastic storage case with soft grip handle and a fully fitted component tray. Manufactured and tested generally in accordance with DIN 3122 and ISO 3315 specifications throughout.

1/4" Square Drive — Precision and Security from 4mm Upward

The 1/4" drive platform provides the STK149N/SG's precision capability for fine, low-torque fastening tasks across electronics, trim, sensor work, and small-format mechanical assembly — with an accessory and bit specification that extends its capability well beyond a standard fine-drive section.

13 standard sockets spanning 4mm to 14mm — including the rarely provided 4mm, 4.5mm and 5.5mm — cover the complete fine metric fastener range encountered in automotive interior and trim work, electronics, bicycle maintenance, and precision mechanical assembly. Seven deep sockets from 6mm to 12mm provide extended reach for recessed fine fasteners and long-threaded small bolts across the most frequently required 1/4" drive deep-reach sizes.

Five E-sockets — E4, E5, E6, E7, E8 bring the STK149N/SG's 1/4" drive section into specialist territory that most sets of any piece count do not address. E-sockets are external Torx sockets designed to drive E-profile fasteners — the convex Torx-star profile increasingly used in modern automotive engineering on engine mounts, exhaust manifolds, drivetrain components, and suspension assemblies where conventional hex or socket head fasteners have been replaced. Small-format E-sockets (E4–E8) are found on the fine fasteners of modern engine ancillaries, electronic component brackets, and precision assemblies — and their inclusion on the 1/4" drive platform of the STK149N/SG reflects a genuinely professional approach to modern vehicle coverage.

The 1/4" drive accessory suite includes wobble extension bars in 50mm and 100mm, a sliding T-bar for leverage and rapid run-down, a spinner handle for fast low-torque socket operation, and a universal joint for angled fine-fastener access.

The 1/4" drive bit selection covers slot bits (4, 5, 6, 7mm), Phillips cross-slot (No.1, No.2, No.3), Pozidrive PZ (No.1, No.2, No.3), and four hex bits (3, 4, 5, 6mm). The Torx provision on the 1/4" platform is exceptional: 8 standard TX-STAR® Torx bits (T8–T30) including the critical T27 for automotive brake and suspension fasteners, paired with 8 matching tamperproof Torx socket bits (T8–T30) for the security Torx fasteners with the central pin that defeat standard Torx bits. This tamperproof Torx coverage on the 1/4" platform — addressing the security fasteners found on automotive ECU brackets, body panels, and access-restricted components — is a differentiating specification that places the STK149N/SG ahead of most competing sets regardless of piece count.

3/8" Square Drive — The Versatile Core of the Set

The 3/8" drive platform delivers the STK149N/SG's general-purpose automotive capability for the broad middle ground of engine, chassis, and bodywork fastening tasks where 1/4" drive lacks strength and 1/2" drive is unnecessarily powerful.

10 standard sockets from 10mm to 19mm cover the core metric fastener sizes most frequently reached for in everyday automotive servicing — engine ancillaries, cooling system components, electrical fixings, brake hardware, and chassis fasteners that account for the majority of workshop fastening tasks. Six deep sockets from 10mm to 15mm extend the 3/8" drive coverage into the recessed and long-threaded fasteners most commonly encountered in this size range on modern vehicles.

Five E-sockets — E10, E11, E12, E14, E16 represent the most important E-socket sizes in professional automotive work. Mid-range E-sockets in this specification are found on exhaust manifold studs, engine mount bolts, catalytic converter fixings, suspension top mounts, and the drivetrain components of a wide range of European, American, and Asian vehicle platforms. Their inclusion on the 3/8" drive platform — where the torque capability is well matched to the force requirements of these applications — reflects the reality of modern vehicle fastener specification more accurately than any set that omits them.

The 3/8" drive accessory suite includes a 150mm wobble extension bar for angled mid-depth access, a universal joint for obstructed fastener engagement, a 3/8" drive coupler, and a 10mm spark plug socket covering the thread size used on the smallest petrol engine spark plugs.

1/2" Square Drive — High-Torque Power with Specialist Coverage

The 1/2" drive platform delivers the high-torque capability required for wheel nuts, suspension components, drivetrain hardware, and the large structural fasteners that define demanding automotive work — with a specialist socket and bit selection that extends beyond the standard automotive range.

17 standard sockets from 10mm to 32mm cover the complete automotive metric range from engine ancillary fasteners through the substantial upper-end sizes of 27mm, 30mm and 32mm for wheel hubs, axle components, and large structural fixings. Five deep sockets in 16, 17, 18, 19 and 22mm address the most frequently required deep-reach sizes in the upper 1/2" drive range — wheel studs, deep-set suspension bolts, and large recessed engine fixings that standard sockets cannot fully engage.

Three E-sockets — E18, E20, E24 complete the E-socket coverage across all three drive platforms, addressing the large-format external Torx fasteners found on heavy suspension components, large engine mounts, propshaft fixings, and the substantial drivetrain fasteners of larger vehicles and light commercial applications. The E18, E20, and E24 sizes are among the most commonly specified large-format E-socket sizes in professional automotive and light commercial vehicle maintenance.

Two spark plug sockets in 12mm and 14mm cover the most widely used spark plug thread dimensions across petrol passenger cars and light commercial vehicles, with the deep-reach design and protective rubber insert required for safe ceramic insulator removal. A three-way adaptor enables three simultaneous socket or accessory connections from a single 1/2" drive source — useful in assembly jigs, simultaneous fastening applications, and complex access configurations.

Two wobble extension bars in 125mm and 250mm enable off-axis 1/2" drive access across two reach lengths, and a 1/2" drive coupler completes the high-torque drive accessory suite.

The 1/2" drive bit selection is built around the large-format Torx and security Torx fasteners found in heavy automotive, commercial, and agricultural applications. Six TX-STAR® Torx bits from T30 to T60 cover the large-format Torx sizes used on suspension subframes, gearbox and differential casings, axle components, and large agricultural and plant machinery fasteners. Eight matching tamperproof TX-STAR® bits from T30 to T60 address the security Torx fasteners at the same large-format sizes — covering the tamper-resistant fixings found on commercial vehicle body panels, restricted access components, and agricultural equipment. The 5 hex bits in 7, 8, 10, 12 and 14mm address large-format Allen-head fasteners across automotive, engineering, and construction applications. Slot bits (8, 10, 12mm), Phillips (No.3, No.4), and Pozidrive PZ (No.3, No.4) complete the 1/2" drive bit suite for large-format screw driving across the full range of head profiles.

Five Hex Keys — Fine-Format Allen Coverage

Five hex keys in 1.5mm, 2mm, 2.5mm, 3mm and 4mm complete the STK149N/SG's coverage of the very smallest Allen-head fasteners found in precision instruments, electronic assemblies, bicycle components, and fine mechanical work — sizes where even the smallest 1/4" drive hex bit shank is too large to access the socket, and where a traditional hex key is the only practical tool.

The E-Socket Advantage — Why Modern Automotive Work Demands Them

A defining capability of the STK149N/SG that separates it from the majority of comprehensive socket sets — including the TK150N/SG — is its inclusion of 13 E-sockets across all three drive platforms. E-type external Torx sockets address the convex E-profile fasteners that have become increasingly prevalent across modern European vehicle platforms in particular, where they are specified for their superior torque transmission, reduced risk of fastener damage, and resistance to the rounding-off that affects hex-head fasteners under high torque. Without E-sockets, a workshop encountering these fasteners on modern BMW, Mercedes, VAG Group, Volvo, and Ford platforms — among many others — must source additional specialist tools to complete jobs that the STK149N/SG handles as standard.

Complete Contents at a Glance

1/4" Square Drive

3/8" Square Drive

1/2" Square Drive

Additional Tools

❓ FAQ Section

What are E-sockets and why are they important for modern vehicles?E-sockets (also known as external Torx sockets) are designed to drive E-profile fasteners — a convex, external Torx-star shape increasingly used in modern automotive engineering, particularly on European vehicle platforms. E-type fasteners are found on exhaust manifolds, engine mounts, suspension components, drivetrain assemblies, and catalytic converter fixings across BMW, Mercedes, VAG Group (Volkswagen, Audi, Seat, Škoda), Volvo, Ford, and many other manufacturers. Without E-sockets, these fasteners cannot be driven — making them an essential requirement for any professional working on modern vehicles. The STK149N/SG includes 13 E-sockets across all three drive platforms (E4–E8 on 1/4", E10–E16 on 3/8", E18–E24 on 1/2"), providing comprehensive coverage of the E-profile fastener sizes encountered across the full range of automotive, light commercial, and engineering applications.

What is the difference between standard Torx bits and tamperproof Torx bits?Standard Torx bits have a solid star-profile tip that engages conventional Torx fastener heads. Tamperproof Torx bits (also called security Torx) have a hollow centre to accommodate the small raised pin in the socket of tamper-resistant Torx fasteners — which are designed specifically to defeat standard Torx bits. Tamperproof Torx fasteners are found on vehicle body panels, ECU and electronic component brackets, restricted-access maintenance points, and increasingly on automotive drivetrain and suspension components. The STK149N/SG includes 16 tamperproof Torx bits in total — 8 on the 1/4" drive platform (T8–T30) and 8 on the 1/2" drive platform (T30–T60) — providing security Torx coverage across the full range from fine electronics fasteners through to large automotive structural fixings.

How does the STK149N/SG differ from the TK150N/SG? Both are 149/150-piece three-drive metric socket sets in the Draper Expert range, but they are built around fundamentally different specialist strengths. The STK149N/SG leads with E-socket coverage on all three drive platforms and tamperproof Torx bits on both 1/4" and 1/2" drive — making it the superior choice for modern vehicle servicing where E-profile and security Torx fasteners are routine. The TK150N/SG includes imperial sockets on all three drive platforms and 10 combination spanners — making it the stronger choice for workshops handling mixed metric and imperial fastener work. The STK149N/SG also adds a 3/8" drive coupler and 1/2" three-way adaptor not present in the TK150N/SG, while the TK150N/SG includes a broader screwdriver bit range. Both represent the top of the Draper Expert socket set range; the correct choice depends on whether modern vehicle E-fastener and security Torx work, or imperial/spanner coverage, better matches the buyer's primary work profile.

Why does the STK149N/SG include T27 in the Torx bit selection?T27 is specified for the STK149N/SG's 1/4" drive Torx range because it is increasingly used in automotive brake caliper bolts, suspension components, and steering system fasteners on European vehicles — particularly from the VAG Group and other German manufacturers. T27 is frequently absent from budget and mid-range bit sets, making it a notable inclusion that signals the STK149N/SG's genuine professional automotive orientation.

What is the three-way adaptor on the 1/2" drive used for? The 1/2" drive three-way adaptor allows three sockets or accessories to be connected simultaneously from a single 1/2" drive source. This is useful in assembly jigs, simultaneous multi-fastener tightening applications, and complex access configurations where multiple drive connections from one tool improve efficiency. It is also occasionally useful for adding a second extension bar or accessory alongside the primary socket connection in restrictive access situations.

Does the STK149N/SG include deep sockets on all three drive platforms? Yes — the STK149N/SG includes deep sockets on all three platforms: 7 deep sockets (6–12mm) on 1/4" drive, 6 deep sockets (10–15mm) on 3/8" drive, and 5 deep sockets (16–22mm) on 1/2" drive. Together these cover the deep-reach requirements across the full socket range of all three drive sizes — addressing the recessed fasteners, long-threaded bolts, and wheel stud applications where standard socket depth is insufficient.

What standards does the STK149N/SG meet? The STK149N/SG is manufactured and tested generally in accordance with DIN 3122 and ISO 3315 — the internationally recognised standards governing dimensional accuracy, mechanical integrity, and performance for socket tools — applied across all three drive platforms and the full 149-piece component range.