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3G Electric
PROTO J4921MCF Metric Open End Crowfoot Wrench, 21 mm, 3/8 in Drive, Chrome - Metric Open End Crowfoot Wrenches
PROTOMetric Open End Crowfoot Wrenches

PROTO J4921MCF Metric Open End Crowfoot Wrench, 21 mm, 3/8 in Drive, Chrome

The PROTO J4921MCF is a metric open end crowfoot wrench made of alloy steel with a chrome finish. It features a 3/8-inch drive size and a 21 mm head size, designed for use with standard ratchets and torque wrenches.

SKU 3G-OTH-315015

Brand
PROTO
Item
J4921MCF Metric Open End Crowfoot Wrench, 21 mm, 3/8 in Drive, Chrome
Part Number
J4921MCF
Category
Metric Open End Crowfoot Wrenches
Available to Order
Also known as:J4921MCFPROTO
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.

Technical Specifications

PROTO
Manufacturer Part Number
J4921MCF
Type
Chrome
Head Size
21 mm
Drive Size
3/8 in

Technical Documents

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PROTO Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The PROTO J4921MCF is a metric open end crowfoot wrench made of alloy steel with a chrome finish. It features a 3/8-inch drive size and a 21 mm head size, designed for use with standard ratchets and torque wrenches.

Frequently Asked Questions

What is the PROTO J4921MCF crowfoot socket wrench used for?

The PROTO J4921MCF is a metric open end crowfoot wrench used to access fasteners in tight spaces where a standard socket or wrench cannot fit. It attaches to a 3/8-inch drive ratchet or torque wrench, making it ideal for automotive, industrial, and maintenance applications requiring precise torque in confined areas.

What are the specifications of the PROTO J4921MCF crowfoot wrench?

The PROTO J4921MCF is made of alloy steel with a chrome finish. It has a 3/8-inch drive size and a 21 mm head size. This metric open end crowfoot wrench is designed for use with standard ratchets and torque wrenches, providing reliable performance in tight-access fastening tasks.

Where to buy the PROTO J4921MCF crowfoot wrench worldwide?

3G Electric supplies the PROTO J4921MCF crowfoot wrench worldwide. As a global industrial equipment distributor since 1990, we handle full logistics, customs clearance, and delivery to your location. Contact us to source this tool for your maintenance or production needs.

How to select the correct crowfoot wrench size for a fastener?

To select the correct crowfoot wrench, match the head size to the fastener's nut or bolt dimension. For the PROTO J4921MCF, the 21 mm head fits a 21 mm fastener. Ensure the drive size (3/8 inch) matches your ratchet or torque wrench. Always verify the fastener's exact size before use to avoid damage.

Used in

Common applications for PROTO
Industrial maintenance — PROTO J6014CXCERT micrometer torque wrench for tightening fasteners to 50–250 ft-lb with tether capability.
Assembly operations — PROTO J6345A electronic torque wrench for 5–50 ft-lb control with audible and visual indicators.
Plumbing and mechanical — PROTO J812HD straight pipe wrench with 2 in jaw capacity for gripping and turning pipes.
Precision fastening — PROTO J61929 multi-bit screw and nut driver kit with 26 alloy steel bits for assembly and maintenance.
Tool organization — PROTO JUC3743-3SG heavy-duty utility cart with drawers, power strip, and padlock for shop floor use.
Metric fastener service — PROTO JSCVM-20SB 20-piece ratcheting combination wrench set covering 6 mm to 32 mm.
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PROTO Products

3G Electric supplies PROTO metric open end crowfoot wrenches. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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PROTO
Metric open end crowfoot wrench with 9 mm head size and 3/8 in square drive. Chrome finish. Designed for use with socket wrenches to access fasteners in confined spaces where a standard socket cannot fit

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