WEN Electric Fiber Cement and Siding Shear (3670) - OSHA Compliant

In this review the WEN Electric Fiber Cement and Siding Shear (3670) is assessed for contractors and serious DIYers who need a fast, OSHA-compliant way to trim fiber cement, Hardie board and similar siding materials. The bottom line: it is a purpose-built, corded shear that consistently delivers clean cuts through up to 1/2 in fiber cement while reducing fatigue thanks to a lightweight 4.7 lb design and lock-on power. For anyone who cuts long runs of siding or shower backer board, the combination of variable speed control and a swiveling head makes repetitive work noticeably easier.

Key Features

• OSHA-compliant cutting: Designed specifically for fiber cement and siding so users can meet jobsite safety expectations while maintaining cut quality.
• 1/2 in maximum capacity: Cuts fiber cement, Hardie board and shower backer up to 0.5 in thick, handling common siding materials without forcing multiple passes.
• Variable speed trigger: Pressure-sensitive control allows fine adjustment from 0 to 2500 strokes per minute for smoother starts and precise cuts.
• 360 degree swiveling head: The pivoting head rotates fully so users can cut at any angle without contorting their grip or body position.
• Reversible steel blades: Included cutting blades are reversible and replaceable and are rated for up to 20,000 linear ft of cutting per set, lowering ongoing blade costs.
• Lightweight, jobsite-ready design: At 4.7 lb with a lock-on switch and 6 ft cord, it balances runtime comfort with practical reach for siding work.

Who It's For

The WEN 3670 is best for professional contractors, siding installers and dedicated DIYers who need to cut long lengths of fiber cement, Hardie board or shower backer board quickly and with consistent edge quality. Its OSHA-minded design and high linear footage per blade set suit users who spend hours on exterior cladding projects.

It is less suited to someone who only performs occasional trim work on thin materials or wants cordless convenience; the 6 ft cord and corded power source make it a shop or jobsite tool rather than a grab-and-go battery device. Also, those who primarily cut materials thicker than 1/2 in or require very large jaw openings for odd profiles should consider alternatives.

Pros & Cons

Pros

• Consistent cut quality on fiber cement and metal sheet surfaces when used as intended.
• Variable speed trigger and lock-on switch reduce operator fatigue during long runs.
• Swiveling head and lightweight body improve ergonomics for angled or overhead cuts.
• Reversible steel blades deliver long service life and are easy to replace.

Cons

• Jaw opening mechanism has mixed feedback from users and can jam if debris builds up, requiring occasional attention.
• Corded design limits reach compared with cordless alternatives.

Specifications

Our Verdict

The WEN 3670 is a practical, cost-conscious choice for anyone who regularly cuts fiber cement and siding and needs a reliable, OSHA-compliant tool. It pairs strong cut quality and long blade life with ergonomics that reduce fatigue, making it good value for contractors and serious DIYers, though occasional users who need cordless flexibility or larger jaw openings should look elsewhere.

Frequently Asked Questions

What thickness of fiber cement can it cut?
The tool handles up to 1/2 in (13mm) fiber cement and up to 5/16 in (8mm) for many other building materials.

How long do the blades last?
The included reversible steel blades are rated for up to 20,000 linear ft of cutting per set before replacement is recommended.

Does the head rotate for angled cuts?
Yes, the swiveling head rotates a full 360 degrees so cuts can be made comfortably at any angle.