
Thread Mills
From UN to Custom: Find Your Perfect Thread Fit
You need threads that fit right the first time—every time. Whether you're machining aerospace components, automotive parts, or high-precision equipment, precision matters. At Scientific Cutting Tools, we design thread mills that help you cut with confidence. Choose from five standard thread styles—UN, UNJ, Metric, Pipe, and ACME—or send us your specs for a fully custom solution. Whatever the job, we’ve got the right tool to keep your shop running smoothly.
UN Threads
Standard Unified National threading
Ideal for general-purpose threading in North American applications
Available in both internal and external options
UNJ External Threads
External threading with root controlled radius
Common in aerospace and high-performance assemblies
Designed for fatigue resistance
Metric Threads
ISO metric threading options for
international standardsAvailable in coarse and fine pitches
Optimized for global compatability
Pipe Threads
Tapered and straight pipe threading (NPT, NPTF, BSPP, BSPT)
Engineered for leak-resistant connections
Suitable for hydraulic and pneumatic
systems
ACME Threads
Strong, load bearing profile
Used in linear motion applications
Multiple pitch and class options available
Custom Threads
We machine to your specs - whether
it’s form, pitch, or coatingIdeal for R&D, specialty OEM applications, and problem-solving
Submit a drawing or consult with our engineering team
Wondering when to use a thread mill instead of a tap?
This video breaks down the key differences - and shows why thread mills can be the smarter choice for tough materials, blind holes, and precision-critical parts.
Emmett Quigley, NASA Ames Research Center
“I love your thread mills.”
Support That Starts
Before the Cut
We don’t just sell tools—we back them with the knowledge and support you need to machine with confidence. Whether you're looking to sharpen your threading strategy or need help on a current job, these resources are here to help.
Thread Milling Webinar. Watch our on-demand webinar to deepen your understanding of thread milling fundamentals, tooling selection, and programming best practices.
DXF and STEP File Downloads. Get CAD-ready files for faster CAM programming and toolpath simulation.
Thread Mill Code Generator. Our calculator takes the guesswork out of programming. Generate your thread milling code based on your specs.
Explore Our Tech Support Pages. From troubleshooting tips to feeds and speeds guidance, our Technical Support hub is your go-to resource.
Still need help? Our in-house engineers are just a click away. Submit a question and we’ll get back to you quickly.