REVIEWING PERFORMANCE OF A THREAD ROLLING TOOL

The long-term performance of a thread rolling tool is directly related to wear of the spindles, bearings, backing plate and face plate of the rolling head. Wear of any components will present initially in pronounced taper of the finished thread.

Older style heads were equipped with needle bearings while newer style heads utilized carbide bushings. The carbide helped to maintain parallel form for longer life cycle than the needles.

Correcting taper generally requires replacing one or more of the contributing components. In a pinch, the straightness is achieved through preparation of a counter tapered part prep. This can squeeze additional life out of the tool without the time and cost of immediate repair or part replacement.

We inspect, evaluate and quote repair cost and time when tool performance becomes questionable, and the inspection is scheduled regarding production needs.

You can teach an old dog new tricks!

For many years in manufacturing the multi spindle screw machine was the dominant metal working tool available worldwide. With short cycle times attributed to several different machining processes occurring at the same time each on a different spindle. The machine technology generated specialized tooling to integrate within the individual spindle cycle time. The machines demanded highly trained specialized set up technicians and because of the set up demands the set-up time required practical lot sizes to make them cost effective. During their heyday most manufacturers offered apprentice programs and controlled training cycles to ensure that talented people were available to support their manufacturing plan. Many of these machines are still in use and still productive. Done right they still offer the lowest cost per piece in the machining industry.

In today’s world the programmable CNC has become the dominant tool for metal working. Skill sets have transitioned from hands on tooling changes to computer literacy. Small lot sizes pose no problem to cost per piece. Cost per piece can be influenced by design of the part to be produced. Threaded parts and long journals can add many passes to a single point turning tool. Journal lengths greater than 6 times diameter require several passes to machine and become even more difficult in smaller diameter parts.

Every second of cycle time has an associated cost and cycle time is the highest cost when compared to tooling. Bidding for work within a job shop atmosphere is directly tied to cycle time. Quoting a job requires careful attention to cycle time if you want to garner a contract and maintain profitability. Some of the tooling technology developed for automatic screw machines has had a natural transition to the CNC world. Thread rolling is an example, the ability to produce threads typically at 1 inch of thread length in 1 second of cycle time is common. Turning of journal lengths up to or greater than 10 times diameter is easily achieved. While there are a variety of tools commonly called “Hollow Mills”, one stands out.

Genesee Tool Co. offers a multi flute, indexable carbide hollow mill that easily and accurately adjusts to part diameters. A three-flute tool, for example, feeds at three times the speed of single point turning. Long journals can be machined in a single pass. Multiply the seconds saved per piece by the number of pieces to be produced and you can quickly calculate the value. It may prove to be the difference between a bid and a contract. Talk to us about your needs, we may be able to offer a solution to optimize your process and improve your bidding results. 

Procedure for 1/2-13 UNC Roll On Roll Off® Thread Rolling System, Patent Pending

Tool setup

  •  Mill a .250” to 375” flat on the shank within .500” of the head if not already there.
  • The tool is assembled and setup.  The rolls are set with a gauge pin to the max Minor less .002”. see below

Machine setup

  •  Mount tool and sweep faceplate OD with an indicator – TIR total .005”

Process setup

  • Use sacrifice material-  program a .600” length to test roll a .500” long part,  Insure the material will not hit faceplate.
  •  Pre-turn for rolling = Mean of the Pitch or __.445”__
  • 30’ chamfer starting at  .015” under min. Minor. ___.372”____
  • Feed rate is Pitch less .0005” or ___.0764”__ Roll on and off at the same federate.
  • Sync tap (G84, G77) works best.   G34 with M03,04 spindle reverse- no dwell.
  • SFM- 125 SFM for low carbon steels, 100 SFM for SS and hi-nickel.  Increase after good part.  Call for confirmation.

Call before you hit cycle start.     704-849-9209  

Adjusting after first test roll-

Step 1- Minor Dia. and Pitch Adjustment-

  • Loosen 3 nuts and adjust tool +/-.  One witness line is .004”on Minor.  Center Pitch. 

Step 2- Major Adjustment-

  • Adjust pre-roll dia to the mean of the Major.  .001” change in pre-roll dia. = Major dia. change of .003”

Step 3- Adjust chamfer

  • Adjust for desired result.  Keep chamfer min of .010 under min Minor.  Material will “rollup about 15’. Alternative- cut after rolling.

Thread Rolling Tool Performance

The long-term performance of a thread rolling tool is directly related to wear of the spindles, bearings, backing plate and face plate of the rolling head. Wear of any or all these components will manifest initially in pronounced taper of the finished thread. Older style heads were equipped with needle bearings while newer style heads utilized carbide bushings. The carbide helped to maintain parallel form for longer life cycle than the needles. Correcting taper generally requires replacing one or more of the contributing components. In a pinch, the straightness is achieved through preparation of a counter tapered part prep. This can squeeze additional life out of the tool without the time and cost of immediate repair or part replacement.

We inspect, evaluate and quote when tool performance becomes questionable. Call us.

Why Form Tap? Better Yet, Why Use Carbide To Form Tap?

The answer to both questions is WHY NOT? Form tapping is internal thread rolling. It offers the same advantages as thread rolling an external journal.

  • Faster cycles.
  • Longer tool life.
  • Stronger threads with at least a 40% improvement in tensile strength.
  • Much higher yet in difficult to thread materials.
  • Most importantly, cost per thread and cycle time.

We can all agree that cycle time is the greatest contributor to overall part cost.  Indeed, TIME IS MONEY.

What materials can be form tapped? Aluminum, the higher tensile strength of a form taped Aluminum part makes it a choice for carbide form tapping but the advantages don’t stop with Aluminum. Let’s explore the other materials that benefit from form tapping with carbide. Low carbon steels A36, 1005-1029, Free steel 1213,12L14. Medium carbon steels 1030-1055, 4130. Heat treatable steels 4140,6150. Cast Steel and Stainless steels 400 series,17=4PH,15-5PH. Aluminum, pure,6061T6,6063. Copper alloys, long chipping. Brass 7075. Magnesium alloys, Thermoplastics 40-70 Newton meters. All the materials mentioned run at operating speeds from 65 to 200 SFM. Imagine the return on tooling investment with 3-5 times the speed of powdered metal and ten times the life.

If your job shop depends on part cost to successfully bid for job opportunities, form tapping is too beneficial to ignore. We offer two styles of traditional form taps. Solid carbide and carbide nib tap heads mounted on a steel shank for lateral strength. The latter style is produced by only one manufacturer, LMT Metalworking Germany.

The most dramatic application we’ve been a part of was a transfer line running a stainless-steel part. The very best performance they could achieve with a powdered metal tap was 300 holes. This forced a shutdown of the transfer line every 300 pieces to replace the tap. The carbide nib replacement tap ran a full shift of 7000 pieces before tap change. The reduction in down time was staggering. The value of the higher cost carbide nib tap was beyond everyone’s expectation.  

What do you run? Are you ready to experience tooling performance beyond expectation? Contact us to discuss your application. We’d like to offer a solution that will change everything you thought you knew about tapping.

What’s Old Can Be New Again

Not only does this phrase apply to our ability to service and repair existing thread rolling tools, frequently we are asked about trade-ins. We will, on occasion, service and sell used tools taken on trade for new purchases.

Many of our loyal customers are commercial job shops that survive by bidding for work against competitors. Thread rolling can dramatically reduce the cost of production by dramatically reducing the time required to thread while improving thread quality and performance. 

Frequently, we have a customer that currently owns a Fette thread rolling head that lacks the capacity to run the part they presently need. If they anticipate no or little need for their present tool, we can extend a trade in agreement that will reduce the acquisition cost of the new tool.

Our goals are simple, the trade in must be in renewable condition. We need to inspect before acceptance to be certain the tool is indeed rebuildable. Much like the cost of building a car at home from the purchase of parts, the same can be true of rebuilding a thread rolling tool. Repair costs can easily exceed the value of a “used” tool. When we accept a trade, we anticipate restoring the tool to good operating condition and resell at considerable savings.

Used tools are available for sale but typically in limited style and supply. They are always sold on a first come basis. Our service and supply ability is geared to extending maximum value to all our customers from the largest manufacturers to our smallest job shops.

We recognize that your success is heavily dependent on cycle time and tool cost. Our success depends on our ability to contain your costs and provide the very best in service. If you have a specific threading issue contact us, we probably have your solution.

Thread Roll Placement

The recent “coating” of thread rolls hides the laser markings and makes it difficult to read the letters and numbers etched on the rolls. To help identify the correct faces of each roll for proper use, see the description of each roll and how they interface for correct alignment. Proper alignment of each roll is done with an understanding of the roll design.

Roll number 1 & A have the same lead on each side of the roll. When changing from numbers to letters it simply requires a flip of the roll on the same spindle.

Roll #2 has a C on the other side. When flipping the roll to the lettered side it requires moving it from position 2 to position 3 on the spindles.

Roll #3 has a letter  on the other side. It requires a flip from position 3 to position 2 on the spindles.

A graphic representation of roll position accompanies this explanation. When constructed only two roll designs are ground.   Flipping and placement create the three roll configuration. Understanding of the placement makes the marking unnecessary.

A Safe Port in A Storm

This has been an objective of mankind since the invention of the ship.  The statement has grown to reflect shelter conditions in virtually any objective.

With the advent of Covid-19 the importance of a “Safe Port” has become a global objective. As a supplier to both big and small businesses our commitment is to continue “business as usual” within the circumstances surrounding us. Our supply from Italian manufacturers is limited due to the situation in their country.  Please keep our Italian friends in your thoughts and prayers.

However, most our suppliers are maintaining operations and many of our customers and suppliers are considered “Essential Businesses” and will continue in operation.  These Many parts of our country are still operating and require the same technical resources they were accustomed to during normal times.

We have added protection to our staff by initiating a “work from home policy,” limiting office staffing to handle shipping and answer phones.  Fortunately, this digital age makes it possible for us to practice social distancing within physical office and warehouse spaces and allow our home bound staff have the resources needed to serve you as usual.

Our team is available to answer your phone calls and emails.  We are eager to support you, process your orders and supply technical assistance whenever needed. Contact us with your individual needs, we’re here to help!.

Knurling and Swaging Made Easy

Fette thread rolling tools have versatility and can be applied to rolling other forms besides external threads. Knurling and swaging applications are easily done on axial, tangential and radial tools with great success. Axial heads are especially successful at rolling straight form, left hand helical, right hand helical and diamond knurl patterns.

The displacement of material forming the knurl pattern exhibits no sharpness in the formed knurl. This is especially important when handling knurled instruments wearing delicate gloves. Very fine to very course patterns are achievable and tooling set up is extremely easy. The application of rolling speeds, like threading, makes cycle times extremely short. This makes the tool application very cost effective.

Swaging is also easily adaptable and the axial approach to swaging yields consistent product quality hard to achieve with a side approach swaging tool. Distortion is nonexistent and swage roll life is extremely high. Symmetrical and step style swage forms can be accomplished. Form coining of nose radiuses is also done frequently. The tools are not limited to straight swage applications.  

If your current tool selection includes thread rolling heads you may not have known that they have applications beyond male threads. Contact us with your Knurling and Swaging applications. We can identify your current tooling and determine if it’s applicable. We can also quote a new application with all the necessary tooling.