We ship worldwide — Singapore, Australia, Malaysia, Indonesia, Philippines, India, Middle East & more

3G Electric
RFQ CartGet a QuoteSign inSign up
PROTO Flex Socket: 3/8 in Drive Size, 11/16 in Socket Size, 6-Point, Std, Chrome - 3/8" Drive SAE Flex Sockets
PROTO3/8" Drive SAE Flex Sockets

PROTO Flex Socket: 3/8 in Drive Size, 11/16 in Socket Size, 6-Point, Std, Chrome

The PROTO J5278HA is a 3/8" Drive SAE Flex Socket with an 11/16" socket size and 6-point standard configuration. It features a chrome finish and is not tether capable.

SKU 3G-OTH-307970

Brand
PROTO
Item
Flex Socket: 3/8 in Drive Size, 11/16 in Socket Size, 6-Point, Std, Chrome
Category
3/8" Drive SAE Flex Sockets
Available to Order
Trade pricing by quote — replies within 24h
Qty
WhatsApp an engineerMessage via Telegram
No account needed — your quote request goes straight to our engineers. A free account lets you track quotes and re-order faster.
Worldwide Shipping
Air & sea freight
Datasheet on Request
Technical specs
1-Day Quote
Replies within 24h

Local availability & support

Delivery
Worldwide DHL shipping from Singapore; 7–14 business days door-to-door for most destinations.
Payment
Invoicing in USD. Bank transfer (SWIFT) and corporate PO accepted.

Technical Specifications

PROTO
Manufacturer Part Number
J5278HA
Type
6-Point, Std, Chrome, Not Tether Capable
Socket Size
11/16 in

Technical Documents

No technical documents available for this product.
Request documentation →
Not sure this is the right part? Get a recommendation.

Need installation or engineering help?

Installation, commissioning, maintenance plans, system design, and bundled product + service quotes — one team handles the full scope.
Talk to an engineer

Ask a question

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

Product Description

The PROTO J5278HA is a 3/8" Drive SAE Flex Socket with an 11/16" socket size and 6-point standard configuration. It features a chrome finish and is not tether capable.

Frequently Asked Questions

What is the PROTO J5278HA flex socket used for?

The PROTO J5278HA is a 3/8" drive SAE flex socket used for turning fasteners in tight or offset spaces. Its 11/16" 6-point chrome design suits automotive, industrial, and maintenance applications where a standard socket cannot reach.

What are the specifications of the PROTO J5278HA flex socket?

The PROTO J5278HA has a 3/8" drive size, 11/16" socket size, 6-point standard configuration, chrome finish, and is not tether capable. It is manufactured by PROTO under part number J5278HA.

Where to buy the PROTO J5278HA flex socket worldwide?

3G Electric supplies the PROTO J5278HA flex socket worldwide. We handle full logistics, customs clearance, and delivery to global destinations as an industrial equipment distributor established in 1990.

How to select the correct PROTO flex socket size?

To select the correct PROTO flex socket, match the drive size (3/8") to your ratchet, and the socket size (11/16") to the fastener. The 6-point design provides better grip on hex bolts, and the chrome finish resists corrosion.

Used in

Common applications for PROTO
Automotive assembly — PROTO J72102 impact socket set for fastening lug nuts on production lines
Heavy equipment maintenance — PROTO J3772T flare nut wrench for hydraulic line fittings on excavators
General industrial repair — PROTO J795SA adjustable wrench set for tightening bolts on conveyor systems
Aerospace manufacturing — PROTO J5240A slotted bit socket for adjusting fasteners in confined spaces
Oil and gas pipeline work — PROTO J5438 12-point socket for valve assembly in refineries
Construction site toolkits — PROTO J8179-T500 double box wrench for structural steel bolting

PROTO Products

3G Electric supplies PROTO 3/8" drive sae flex sockets. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

You might also need

Burners & Combustion →Pumps & Compressors →Spare Parts →All Products →

Compatible alternatives & equivalents

Cross-referenced by specification & description
PROTO Flex Socket: 3/8 in Drive Size, 5/8 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5277HA)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 5/8 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5277HA)
PROTO Flex Socket: 3/8 in Drive Size, 9/16 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5276HA)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 9/16 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5276HA)
PROTO Flex Socket: 3/8 in Drive Size, 3/4 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5279HA)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 3/4 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5279HA)
PROTO Flex Socket: 3/8 in Drive Size, 1/2 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5275HA)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 1/2 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5275HA)
PROTO Flex Socket: 3/8 in Drive Size, 7/16 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5274A)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 7/16 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5274A)
PROTO Flex Socket: 1/2 in Drive Size, 1/2 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5475A)
PROTO
PROTO Flex Socket: 1/2 in Drive Size, 1/2 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5475A)

More from PROTO

View all PROTO parts →
PROTO Flex Socket: 3/8 in Drive Size, 7/16 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5274HA)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 7/16 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5274HA)
PROTO Flex Socket: 3/8 in Drive Size, 3/8 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5273HA)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 3/8 in Socket Size, 6-Point, Std, Chrome, Not Tether Capable (MPN J5273HA)
PROTO Flex Socket: 3/8 in Drive Size, 11/16 in Socket Size, 12-Point, Std, Chrome (MPN J5278A)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 11/16 in Socket Size, 12-Point, Std, Chrome (MPN J5278A)
PROTO Flex Socket: 3/8 in Drive Size, 9/16 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5276A)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 9/16 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5276A)
PROTO Flex Socket: 3/8 in Drive Size, 3/8 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5273A)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 3/8 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5273A)
PROTO Flex Socket: 3/8 in Drive Size, 9/16 in Socket Size, 6-Point, Deep, Chrome, Not Tether Capable (MPN J5276LHA)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 9/16 in Socket Size, 6-Point, Deep, Chrome, Not Tether Capable (MPN J5276LHA)
PROTO Flex Socket: 3/8 in Drive Size, 5/16 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5272A)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 5/16 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5272A)
PROTO Flex Socket: 3/8 in Drive Size, 5/8 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5277A)
PROTO
PROTO Flex Socket: 3/8 in Drive Size, 5/8 in Socket Size, 12-Point, Std, Chrome, Not Tether Capable (MPN J5277A)