Maximizing Thread Precision and Tool Longevity with CJWinter’s 193 End‑Rolling Attachment

Air‑Way, the nation’s largest independent hydraulic fittings manufacturer, has partnered with CJWinter to integrate the 193 end‑rolling attachment into its Buffoli CNC rotary transfer machines. This collaboration demonstrates the attachment’s ability to deliver high‑quality threads on both sides of a part while maintaining rapid production speeds.

Thread rolling is a cold‑forming process that displaces material using hardened rolling dies to produce threads, splines, or knurls. Compared with traditional thread‑cutting, thread rolling offers strengthened tooth geometry, superior surface finish, tighter tolerances, and faster cycle times.

End rolling rolls the thread onto a rotating part by moving the rolling head linearly along the part’s axis, allowing the tool to be positioned with extreme precision.

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According to CJWinter, the 193 end‑rolling attachment incorporates several design innovations that set it apart from conventional units:

• One‑piece front plate with integral standoffs for a robust, low‑profile construction.
• Sealed pitch‑adjustment gear trains and fine‑adjust screws that simplify setup and ensure repeatable positioning.
• Low‑friction, ultra‑hard coatings on the twin plates that nest the thread rolls, reducing wear and extending tool life.
• Reduced component count, which translates to a lighter footprint (15 lb) and easier machine installation.
• Through‑coolant capability that keeps the rolls lubricated and eliminates chip buildup on both the workpiece and tooling.

The attachment can be fitted with either a 1.5‑inch diameter shank or a CAT40 shank, providing flexibility for a wide range of applications and enhanced rigidity.

Adjusting the spacing between the three rolls requires only three locking screws and a single twist of the head. This single action moves all rolls equally, ensuring uniform load distribution and maintaining concentricity relative to the part’s centerline.

Unlike conventional end‑rolling heads that spring open to clear threads and then retract, the 193 rolls on, stops the spindle, and then reverses as it rolls off. This reversible action delivers a double‑burnish effect, producing a smoother finish and extending tool life by roughly 100 %.

“Thread rolling provides a burnishing effect that produces a superior finished form,” says Liberato Pietrantoni, CJWinter’s Director of Global Sales. “The 193’s roll‑on and roll‑off cycle creates a double‑burnish that is especially valuable for hard materials.”

Because the 193 eliminates the need for internal spring‑opening mechanisms, it weighs 15 lb—significantly lighter than the typical 40 lb of conventional heads—reducing spindle wear and shortening setup time to under an hour.

Rotary Transfer Case in Point

Last year, Production Machining reported that Air‑Way added its first Buffoli CNC rotary transfer machine to its Hamilton, Indiana facility. The family‑run company, renowned for its high‑volume hydraulic fittings, subsequently installed a second machine and began testing the CJWinter 193 end‑rolling heads.

Hydraulic fittings produced in large quantities on rotary transfer machines are ideal candidates for thread rolling, as the process delivers consistent, high‑quality threads with minimal tooling wear.

Air‑Way’s engineering team collaborated with CJWinter to tailor the 193 attachment for its complete product line, sometimes fitting two units on a single machine to accommodate fittings that require threads on both sides.

Through rigorous testing and close partnership, Air‑Way and CJWinter are validating the 193 attachment’s performance, demonstrating its potential to streamline high‑volume production while enhancing thread quality and tool durability.