6 x 3-1/8 x 3-1/2 in Cast Iron V Block Set - Matched Pair

In this review the 6 x 3-1/8 x 3-1/2 in Cast Iron V Block Set is evaluated for workshop use and basic layout work; it is a simple matched pair of cast V-blocks aimed at machinists, toolroom technicians and hobbyists who need stable support for cylindrical parts. The single biggest reason to consider these blocks is their combination of heavy cast construction and machined square faces, which provide a reliable, low-cost platform for holding round stock during marking, drilling or basic inspection tasks.

Key Features

• Matched pair: Supplied as two blocks so cylinders can be supported on both sides for stable setup during machining or measuring.
• Machined faces: Square and parallel surfaces are machined to standard specifications to ensure consistent seating and predictable alignment.
• High quality casting: Properly seasoned casting reduces the risk of distortion and gives a heavy, stable base for general shop work.
• V width and depth: A 3-1/8 in V width and 2-1/2 in depth hold a variety of round stock sizes without expensive fixturing.
• Size and weight: At 6 in length and about 13 lbs total weight, the set offers good mass for damping vibration and resisting movement under light loading.

Who It's For

This set is best for general machinists, maintenance technicians and hobbyists who need an affordable, solid support for turning, drilling or basic inspection of round parts. Its machined faces and matched pairing make it practical for layout work, quick setups and non-precision holding where mass and stability matter.

It is not intended for high-precision gauge work or metrology labs that require certified, hardened or ground V-blocks. If absolute dimensional accuracy and certified calibration are required, look for hardened, ground blocks with calibration certificates instead.

Pros & Cons

Pros

• Solid cast construction and substantial weight give stable support for general shop tasks.
• Machined square and parallel faces provide predictable seating and alignment for routine setups.
• Sold as a matched pair so parts can be supported on both sides without additional fixtures.

Cons

• Not a precision gauge set; some users report mixed accuracy and occasional quality variation between pieces.
• Cast iron construction can be brittle under severe shock or improper handling.

Specifications

Model	6 x 3-1/8 x 3-1/2 in Cast Iron V Block Set
Pair	Supplied in a matched pair
Length (A)	6 in
V width (B)	3-1/8 in
Height (C)	3-1/2 in
Depth (D)	2-1/2 in
Weight	Approximately 13 lbs (set)

Our Verdict

The 6 x 3-1/8 x 3-1/2 in cast iron V block set is a practical, cost-effective choice for workshop tasks that need stable support of round stock. It offers good value when machined faces and matched pairing are sufficient, but those needing precision metrology should choose hardened, certified alternatives. For general machinists and hobbyists it is a useful, heavy-duty workholding aid.

Frequently Asked Questions

Are these V-blocks hardened or ground?
No, these are cast and machined to square and parallel; they are not indicated as hardened or ground precision gauge blocks.

What size stock will the V accept?
The V width is 3-1/8 in with a depth of 2-1/2 in, suitable for a wide range of small to medium cylindrical stock used in general shop work.

Do they come as a matched set?
Yes, the product is supplied in a matched pair so two blocks can be used together for stable support.