Acme vs. Trapezoidal Threads - What's the Difference?

Acme vs. Trapezoidal Threads - What's the Difference?

Acme threads appeared sometime in the late 1800's, as an improvement on the square thread form. Square threads were the first choice for motion transfer and heavy loads. But, square threads were difficult to produce with available cutter technology. Although the square form was relatively efficient for the purposes required, it was inherently weak at the base of the thread due to the sharp 90-degree angle of the flank. Modifying the included-angle to 29-degrees widened the base of the thread making it stronger. Over time, standards in Acme diameters and pitches were established, all with Imperial Inches in diameter and Threads-per-Inch units of description.

Tags: Acme, Threads, Trapezoidal

North American Tool President, Curt Lansbery, receives ISA’s Golden Eagle Award

Curt Lansbery has been chosen as a recipient of the ISA’s Golden Eagle Award for his 28 years of valued contributions to the industry.  The award was presented by the President of IBC, Ron Nunez.

Tags: Curt Lansbery, IBC, ISA Golden Eagle Award, North American Tool, President

North American Tool Celebrates #MFGDAY16

On National Manufacturing Day, American manufacturers open their doors and take up the important work of inspiring our young people to pursue careers in manufacturing and engineering. North American Tool was honored to host Beloit Memorial High School for MFG DAY 2016.  Students got to experience the entire tap manufacturing process observing how our associates operate their machines, and the wide variety of products we manufacture. 

Tags: MFGDAY16, North American Tool

Surface Treatments & Coatings

 Surface treatments and coatings allow us to improve tooling performance when the characteristics of the tool's substrate (base material) have reached the limits of capability. Surface treatments like Oxide and Nitride were among the early arrivals. They addressed the need for added lubrication and surface hardness to improve part finish, reduce or tolerate heat generated by higher machining speeds, and wear-resistance.

 As materials evolved, so did the available treatments to either improve tool performance, or compensate for the challenges those new materials presented to Manufacturing.  Hard coatings like Titanium Nitride (TiN) offered improvements in wear-resistance for HSS tooling. Titanium Carbon-Nitride (TiCN) arrived to compensate for the limitations of TiN, especially in respect to Titanium Alloys. Titanium Aluminum Nitride (TiAlN) followed with improved tolerance to heat generated by increasing machining speeds and material resistance to the tool. Each new coating is developed to succeed where another was not well-suited to the application.

Tags: coatings, cutting tools, Nitride, surface treatments, TiAlN, TiCN, TiN, treatments

Chasing or Re-threading Tapped Holes

Are you trying to "chase", or clean-up existing internal threads? Use a tap designed for the job at-hand.

When we at North American Tool are informed that a tap is to be used for " re-threading", another term for this task, we always recommend at tap with 0-3 degree Rake for the cutting edge.

Tags: chasing tapped holes, cleaning up threads, re-threading

Recipients for Annual Taylor Memorial Scholarship Named

North American Tool Names Recipients of 2016 Taylor Memorial Scholarship

Tags: Taylor Memorial Scholarship

Cutting Taps vs. Forming Taps

Cutting Taps vs. Forming Taps

A significant majority of the threads produced in manufacturing today are machined with cutting tools: typically taps and thread-mills for the internal threads, and threading dies and thread-mills for the external threads. These tools are the historical standard for this purpose, and a familiar go-to for machinists. As machined materials and applications change with customer demand, alternatives for tooling follow suit. Although both cutting tools and forming tools produce essentially the same thread, and are gaged in the same manner, the requirements for their use, and results achieved, are in many ways different.

Tags: Cutting Taps, Forming Taps

Selecting The Style Of Tap To Use


You need a tap. What information is needed, and how do you choose the right tap for the job?

When you call North American Tool, we will ask for the basic thread description which specifies the diameter, thread pitch or TPI, the Class-of-Fit (for gaging purposes), and the thread type (e.g. 60-degree, Acme, Buttress, Whitworth, Pipe, etc..). All of these features should be called out by the customer, or included on the Part Print.

Tags: Tap Selection

British Standard Pipe (BSPP/ BSPT): Whitworth Full Form vs. Modified

Whitworth Threadform

Proposed as a method of thread geometry standardization in the mid 1800’s, Whitworth threads – both Full Form and Modified- feature a 55 degree included angle.  The notable differences in these forms are illustrated in the graphic.

The true specification for 55 degree Whitworth is “full form”, which has a radius crest and radius root on the thread.

Tags: British Standard Pipe, BSPP, BSPT

Being Prepared: Hole Preparation Prior to Tapping

Machine Tap

Hole preparation is often a forgotten consideration when threading a part. Depending on the parameters of the application, lack of attention to the size and condition of the hole can contribute greatly to thread size and finish, or the potential failure of the tap.

Holes to be tapped are straight or tapered. They can be cored, drilled, bored, punched, and extruded, all with or without reaming to finished size. Each one of these methods for producing a hole have inherent areas of concern.

Tags: hole preparation, threading a part