Klein 651MQS Quad-4 metric impact flip socket set displaying 7mm, 10mm, 12mm, and 8mm color-coded sizes on a 1/4-inch drive adapter.
Diagram detailing 4 metric sizes in 1 socket body, color-coded rings, deep-well design, and impact-rated alloy steel construction.
Diagram demonstrating spring-loaded coaxial action where applying pressure retracts inner sleeve walls to engage larger metric hex heads.
Overview of included components showing the Klein Quad-4 metric flip socket alongside its 3.5-inch impact extension adapter shank.
Klein 651MQS Quad-4 metric flip socket mounted on a power impact driver chuck to highlight high-torque impact compatibility.
How A Quad Socket Works (651QS, 652QS, 653QS, 654QS and 656QS) promotional video
Klein 651MQS Quad-4 metric impact flip socket set displaying 7mm, 10mm, 12mm, and 8mm color-coded sizes on a 1/4-inch drive adapter.
Diagram detailing 4 metric sizes in 1 socket body, color-coded rings, deep-well design, and impact-rated alloy steel construction.
Diagram demonstrating spring-loaded coaxial action where applying pressure retracts inner sleeve walls to engage larger metric hex heads.
Overview of included components showing the Klein Quad-4 metric flip socket alongside its 3.5-inch impact extension adapter shank.
Klein 651MQS Quad-4 metric flip socket mounted on a power impact driver chuck to highlight high-torque impact compatibility.
How A Quad Socket Works (651QS, 652QS, 653QS, 654QS and 656QS) promotional video
KLEIN TOOLS

Klein Tools Metric Impact Flip Socket Set 651MQS 2 Piece Quad 4 (1/4 Inch Drive 4 in 1 Metric Spring Loaded Steel Hex Fastening Adapter)

Only 2 left
SKU: 651MQS
$19.99 USD

Description

Klein promotional logo logout

Klein Tools 651MQS Quad-4 Metric 4-in-1 Coaxial Heavy-Duty Impact Flip Socket Set

The Klein Tools 651MQS Quad-4 Metric Impact Flip Socket Set provides a compact power driving extension engineered to combine four primary metric hex dimensions into a single dual-ended socket body paired with a 1/4-inch drive adapter shaft. Forged from heat-treated cold-forged steel with a black manganese phosphate protective surface coating, this 14 oz (0.88 lb) impact-rated assembly measures 4.19 inches high by 0.67 inches wide and integrates internal spring-loaded coaxial socket sleeves across 7 mm, 8 mm, 10 mm, and 12 mm hex sizes. Built to endure severe rotational torque and impact vibration, this system allows electricians, automotive mechanics, and panel builders to compress socket walls directly over bolt heads for immediate hands-free size switching without removing the tool from long threaded studs or tight electrical enclosures.

Best Used For:

  • Metric Terminal & Control Panel Bolting: Servicing electrical enclosures, relays, and terminal strips featuring 7 mm, 8 mm, 10 mm, and 12 mm metric hex hardware without swapping individual socket units.
  • Extended Threaded Shaft Fastening: Reaching nuts buried deep along threaded studs in narrow junction bays utilizing a deep-well coaxial socket profile.
  • Impact Driver & Shaft Extension Integration: Mounting directly onto 1/4-inch quick-connect impact drivers or 1/4-inch square drive anvils for rapid power driving.

Key Performance & Safety Features

  • 4-in-1 Quad-4 Coaxial Metric Socket: Houses 7 mm, 8 mm, 10 mm, and 12 mm metric hex sizes within a single dual-ended reversible socket body.
  • Hands-Free Spring-Loaded Action: Coaxial inner sleeve retracts automatically under forward pressure, granting instant access to larger hex dimensions without stopping for manual adjustments.
  • Heat-Treated Cold-Forged Steel Construction: High-grade metallurgy withstands intense rotational impact shock loads without cracking drive walls or rounding fastener flats.
  • Black Manganese Phosphate Coating: Industrial protective surface finish prevents corrosion, rust, and chemical damage from jobsite exposure.
  • Industry-Standard Color-Coded Bands: Vibrant painted identification rings permit rapid visual size recognition inside dark work areas or cluttered tool pouches.

What's Included

  • (1) Klein Tools Quad-4 Coaxial Reversible 4-in-1 Heavy-Duty Metric Impact Flip Socket (7mm, 8mm, 10mm, 12mm)
  • (1) 3-1/2-Inch Extended 1/4-Inch Drive Shaft Adapter

Technical Specifications

Brand Manufacturer Klein Tools®
Model Part Number OEM SKU 651MQS
Tool Classification System Quad-4 4-in-1 Coaxial Metric Impact Flip Socket Set
Core Metallurgy Material Heat-Treated Cold-Forged Steel
Surface Protective Finish Black Manganese Phosphate Corrosion-Resistant Finish
Primary Input Drive Interface 1/4 inch Drive (Includes 3-1/2 inch Shaft Adapter)
Integrated Metric Socket Sizes 7 mm, 8 mm, 10 mm, and 12 mm Hex
Socket Point Profile Geometry 6-Point Deep Well Profile
Fastener Transition Action Hands-Free Coaxial Spring-Loaded Compression & Reversible Flip Body
Visual Identification System Color-Coded Painted Rings
Overall Unit Height 4.19 inches (10.6 cm)
Overall Unit Width & Length 0.67 inches W x 0.67 inches L (1.7 cm x 1.7 cm)
High-Voltage Insulated Frame No (Uninsulated - do not use on energized electrical circuits)
Total Piece Count 2 Pieces (1 Quad Socket + 1 Extension Shaft)
Net Product Weight 14.0 oz / 0.88 lb (397 g)
Global Trade Item Number GTIN 00092644380150

Pro-Tip: To drive 7 mm or 10 mm hardware, press the tool end firmly onto the bolt head so the internal spring compresses completely. To engage 8 mm or 12 mm hardware, simply relieve forward pressure or flip the socket sleeve around to utilize the outer socket wall profile directly.