When it comes to drywall finishing, having the right knife makes all the difference. While they may look similar, drywall knives vary widely in design and performance. In this guide, we’ll break down the different types of drywall knives and how to choose the right knife for the job.
Joint Knives vs. Taping Knives
Taping knives have wide and flexible blades used for spreading joint compound over large drywall seams, ranging from 8” to 14” blades. Joint knives, also called putty knives, have 1” to 10” blades and are meant for smaller jobs like embedding tape, filling holes, or scraping mud.
Key Features of Drywall Knives
One-Piece vs. 2-Piece
One-piece or solid-handle knives are made with a welded, full-tang construction that eliminates weak points for heavy-duty strength. They’re also made of stainless steel, which makes them easy to clean and long-lasting.
2-piece knives on the other hand, feature a separate blade attached to a handle. They are the most affordable option and a popular choice for DIY projects. They have many benefits, including comfortable, rubberized grips for all-day use, added flexibility for smoother finishes, and a wide range of stainless, blue steel, or plastic blade options.
Flexible vs. Stiff Blades
Many drywall pros like to debate which one is better, but it really comes down to personal preference. Stiff blades usually need to be “broken-in” for a more natural feel, but they’re ideal for embedding tape, applying thick mud, and scraping stubborn materials. Flexible blades can spread compounds more easily and bend to follow surface contours, making them perfect for feathering joint edges and working on corners.
Types of Blade Materials
Stainless Steel
- Less flexible, but can still hold a clean edge
- Superior rust and corrosion resistance compared to other steel types
- Low maintenance and ideal for wet conditions
- Best for DIYers, homeowners, and professionals
Blue Steel
- Excellent flexibility compared to stainless steel
- Better rust-resistance than carbon steel
- Requires some maintenance to prevent rust
- Best for experienced professionals looking for added control
Carbon Steel
- Superior flexibility and sharpness
- Highly prone to rust if not cleaned and dried
- Requires more maintenance
- Best for interior and dry conditions
Drywall Knife Size Breakdown
4-inch Knife
Mainly used for flattening paper tape and finishing inside corners. It’s also ideal for tight spaces, filling small holes, and patchwork.
6-inch Knife
The most versatile and commonly used size. Ideal for the first coat of mud, coating screws, and cleaning up edges.
8-inch Knife
Used for the second coat, wiping tape, and smoothing out joint compound after taping drywall seams.
10-inch Knife
Used for the finish coat. It offers a good balance of control and coverage, allowing for effective feathering that blends joint compound smoothly. Some professionals prefer it over a 12-inch knife because it reduces wrist strain.
12-inch Knife
An alternative option for the 10-inch knife, this size offers a wider blade and added flexibility making it excellent for feathering. It’s especially effective for skim coating large areas and smoothing out high spots.
Our Recommended Sets for 2026
Set Includes:
- 4", 5", and 6" Joint Knives
- 8", 10", and 12" Taping Knives
Set Includes:
- 4", 5", and 6" Joint Knives
Where Can I Buy Drywall Knives?
You can find the perfect set of knives for your next project at CSR Building Supplies in-store and online. We offer fast and reliable shipping worldwide, so you can get your tools shipped right to your doorstep.
Contact Us
Call us Monday to Friday between 6 AM and 4 PM at (905) 761-5611
Email us anytime at info@csrbuilding.ca
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