Power chuck soft jaws are an essential workholding solution for CNC lathes and turning centres, allowing machinists to securely clamp parts with greater accuracy and repeatability. Unlike hardened jaws, soft jaws are designed to be machined to match the exact shape of the workpiece, creating a custom gripping surface that improves stability, reduces runout and improves part protection.
Supplied in either solid or indexable form, ideal for machining external radii on all materials.
What Are Hand Taps
Hand taps are cutting tools used to create internal screw threads (female threads) in holes. They are manually turned using a tap wrench or handle rather than in a machine. Hand taps cut threads into pre-drilled holes so that bolts or screws can be properly fitted. Because hand taps are worked manually, they provide control, flexibility and precision, especially in jobs where machine tapping isn’t feasible or safe.
Why Are Hand Taps Used?
Versatility: Hand taps allow for threading in hard-to-reach or awkward positions where machines cannot reach.
Control & Accuracy: They allow for slower, more careful cuts, which can reduce risk of misalignment or damage to the thread.
Cost-Effective for Small Runs: When you're not doing mass-production, hand taps are more economical: no large machinery needed, less setup.
Repair & Maintenance: Ideal for tapping, retapping or cleaning up existing thread holes.
Variety of Materials: From steel to aluminium, plastic, or cast iron—hand taps can be used on a wide range of materials with the correct tap.
What Type of Hand Taps are Available?
Complete Sets:Kits that include first, second and bottom (or taper, plug etc.) taps – useful for full threading operations or for versatility.
First (or Taper) Tap:Called the “starter” tap: has a pronounced taper so it gradually cuts the thread, useful for starting the hole or when aligning is difficult.
Second (or Intermediate) Tap:Less taper, deeper cut than first tap; follows the first to deepen and refine the thread.
Bottom (or Plug) Tap:Cuts thread all the way to the bottom of a blind hole; has very little taper so you can reach full thread depth.
What Thread Forms are Hand Taps Available in?
Hand taps are available in a variety of thread forms to suit different standards and applications. Some of the common thread forms include:
Metric threads(e.g. Coarse & Fine series)
Whitworth threads(e.g. BSW/BSP)
Unified threads(e.g. UNC/UNF/UNEF)
Whitworth British Standard Pipe(e.g. BSP/BSPT)
Acme / Trapezoidal(e.g. for power screws / linear motion)
Buttress Threads
NPT / Tapered Pipe Threads
Special Threads(custom or non-standard) depending on the toolmaker)
Why Buy Hand Taps from Cutwel
Quality & Range:Cutwel offers a broad selection of hand taps, covering first, second, bottom and full sets, in metric, imperial or specialised thread forms — ensuring you get exactly what you need.
Expertise:With decades in the trade, our experts can help you choose the correct tap type and thread form for your material and application.
Reliability & Precision:All our hand taps are manufactured to high tolerances, ensuring accuracy, long tool life and clean threads.
Competitive Pricing:We balance quality with value — you get top-grade taps without overpaying.
Quick Delivery & Support:Fast UK delivery, excellent customer service, and easy returns make buying from Cutwel hassle-free.
Full Product Information:We provide clear specs (thread pitch, diameter, type etc.), so you select the correct item without guesswork.
CNC power chuck soft jaws are machinable lathe chuck jaws used on CNC lathes and turning centres. They are typically made from low-carbon steel or aluminium so they can be bored or milled to match the exact shape of the workpiece.
This creates a custom gripping surface that improves part stability, accuracy and repeatability during machining. Soft jaws are usually machined directly on the chuck to ensure proper alignment with the spindle.
Soft jaws allow machinists to create a custom gripping profile that matches the workpiece. This increases contact area, improves grip and reduces the risk of damaging finished parts. Because the jaws can be bored to a specific diameter, they also improve concentricity and repeatability. Soft jaws are commonly used for precision turning, batch production, delicate components and irregular workpiece shapes.
Hard jaws are made from hardened steel and are used for general-purpose clamping where high gripping force and durability are required. Soft jaws are made from machinable materials such as steel or aluminium so they can be modified to match a specific workpiece. This allows them to provide custom workholding for higher accuracy, better repeatability and improved protection of finished surfaces.
Soft jaws are bored directly on the chuck to ensure the machined diameter is perfectly concentric with the spindle. Machining the jaws under clamping pressure replicates the chuck’s operating conditions and helps minimise runout. If soft jaws were machined off the machine, small alignment differences could cause poor concentricity and reduced accuracy when holding the workpiece.
Soft jaws can be machined to match the exact profile or diameter of a workpiece. This creates a larger contact surface and ensures the part is held securely with minimal runout. Once bored, the jaws allow parts to be loaded in the same position for every cycle, improving repeatability and helping maintain consistent tolerances in production machining.
Cutwel supplies soft jaws designed to fit many of the most commonly used CNC power chuck systems. These include popular brands such as Kitagawa, Chandox, Samchully and other widely used workholding manufacturers.
Soft jaws are produced with standard serration patterns and mounting configurations to ensure compatibility with many hydraulic and power chucks used on CNC turning centres.
When selecting soft jaws, it is important to match the jaw type to the chuck model, serration pitch and chuck size to ensure proper fit and safe operation during machining.
Choosing the correct soft jaws requires matching several key specifications to your existing chuck. The most important factor is compatibility with the chuck system, as soft jaws are designed to fit specific power chuck types such as Kitagawa-style chucks and other common systems used on CNC lathes.
You must also ensure the serration pitch and angle match the master jaws on your chuck. Many CNC power chucks use 60° serrations with 1.5 mm or 3 mm pitch, while other jaws may use 1/16" serrations with a 90° pitch, so selecting the correct serration type is essential for proper engagement and safe clamping.
Other important dimensions include chuck size, keyway width, bolt size and hole centre spacing, which vary depending on the chuck model. For example, soft jaws may be available for chuck sizes ranging from around 4" up to 21", with different keyway widths and mounting dimensions to match the master jaws.
Finally, consider the jaw height and material depending on the application. Standard machinable steel jaws are commonly used for general turning, while specialised soft jaws may be used for high-precision or delicate workpieces. Once installed, the jaws can be bored or machined to match the exact workpiece profile for improved gripping accuracy.
If you are unsure which soft jaws are suitable for your chuck or application, Cutwel’s technical team can provide expert advice to help you select the correct option for your CNC turning setup.
The life of CNC soft jaws can be extended by machining and using them correctly. When preparing the jaws, they should be bored on the chuck under the correct clamping pressure to maintain concentricity and prevent uneven wear. Avoid removing excessive material during machining so the jaws can be re-machined for future setups.
Using the correct jaw material for the application and ensuring proper clamping force will also reduce deformation and damage. Regular inspection and careful handling during setup can help maximise the usable life of soft jaws and improve overall workholding performance.
Cutwel provides a comprehensive range of CNC power chuck soft jaws, from trusted brands such as Bison, Kitagawa, and our own Cutwel Pro, designed for reliable and accurate workholding in turning applications. Our selection includes jaws compatible with many leading chuck brands and available in a variety of sizes, heights and materials to suit different machining requirements.
With high-quality products, expert technical support and fast UK delivery, Cutwel makes it easy to source the right soft jaws for your CNC turning operations. Whether for general machining or precision production work, our workholding solutions help improve setup efficiency and machining consistency.
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