In-die Tapping Reduces the Risk of Untapped Parts

One of the continuing concerns we hear from customers revolves around stamped parts being shipped to a customer without a tapped hole.   This risk can be minimized by using sensors in the tapping station to make sure the tap goes through the stamped part.  This simple and effective process greatly minimizes the risk of shipping untapped parts.

Now compare this with the risk of shipping untapped parts on a secondary operation.  Most secondary tapping operations have a lot of human interaction.  These repetitive types of operation can easily lead to operators skipping a tapped hole on parts with multiple tapped holes.  Low cost automation can eliminate some of the skipped hole problems.  But what about parts where the operator just plain forgets to load into the secondary tapping machine but the parts still wind up in the good part bin.

In-die tapping certainly reduces the cost of parts by eliminating a secondary tapping operation.  In addition, it can also be a tremendous cost saver and customer service winner by eliminating the risk of sending untapped parts to a customer.

Troubleshooting Tips When Breaking Taps

Tap breakage can be a frustrating experience, especially when it is hard to determine the cause of the breakage.  Over the years we have found four things to be the most common causes of tap breakage.

          1.  Incorrect Hole Size:  Hole sizes that are a few thousandths to

                   small can be the difference between success and failure-

                   especially roll forming taps.

          2.  Misalignment:  Taps hitting the hole off center

          3.  Improper Lubrication: Lack of lubrication often leads to poor 

                   tap life but can also lead to breakage.

          4.  Timing Issues:  Taps not getting out of the way of the advancing

                   strip.

Follow Along In-die Tapping Head Die Design Video

The expression that a picture is worth a thousand words is now being replaced by video is worth a thousand words.   Hutchison Tool is happy to introduce our latest instructional video for design characteristics of a die utilizing our follow along In-die tapping heads.  The video can be viewed under the video tab on our website(www.hutchisontool.com).  It can also be viewed on our Youtube channel via this link(http://youtu.be/EH143wec2T0)

Please contact us with any questions or comments you may have on the video as well as any design questions that you may have.

New In-die Tapping Calculator Estimating Tool

NEW In-die Tapping Calculator Estimating Tool

Calculate Press Stroke and Strokes per Minute (SPM) using our new In-die Tapping Calculator.  It’s as simple as plugging in a few basic parameters (thickness, tap pitch, press stroke, etc.) and scrolling to your answers. The In-die Tapping Calculator can be found under In-Die Tapping Resources on our newly updated website, www.hutchisontool.com.  

Click on Application Worksheet on the In-Die Tapping Resources page to download the excel file.  Choose between 2 spreadsheets: one for applications with strip-lift under .125” and the second for those over .125”.  Enter your information and get your answers instantly. We will gladly guide you through the worksheet if further assistance or a unique application is needed. 

2D & 3D In-Die Tapping Head CAD Files Available at HutchisonTool.com

Finish your tapping die design with a few clicks of the mouse.  2D & 3D CAD drawings for all Hutchison In-Die Tapping Head Models are available for download at www.hutchisontool.com.  Simply click on the In-Die Tapping Resources tab for CAD File links.

Once your design is complete our design engineers will gladly review the tapping station via a GoTo Meeting to ensure the in-die tapping implementation of your project is a smooth and trouble free experience.

Be Aware of Burrs with Roll Tapping

The nature of rollform form tapping inherently will cause a bur.  This is due to the fact the rollform tapping forms and displaces material v. cutting out material with cut tapping.  While rollform tapping is a stronger thread than a cut thread, the burs that are produced need to be addressed.  Generally this is done but countersinking the hole so that the burs will not protrude past the top and bottom face of the material.

Another issue that comes up when rollform tapping with In-die tapping is making a clearance hole in the die for the burs from the rollform tapping operation.  If there is not a clearance hole the likely result will be the bur being pushed back into the bottom of the tapped hole.  This will result in having the go gage work to the bottom of the tapped hole and stopping at the last thread. By providing clearance in the die this issue is easily resolved.  

Hutchison Tool introduces HTS Models 3000, 3100, 6000, 6100

Hutchison Tool introduces HTS Models 3000, 3100, 6000, 6100

We are pleased to announce the latest In-die tapping heads with the introduction of the HTS Models 3000, 3100, 6000 and 6100.    These new units encompass several new features while maintaining a large tapping capacity (#2-56 to ½-13 or M2 to M12) and a quick change tap assembly that allows taps to be changed in the press in under a minute.  The following are some of the new features:

• Multiple mounting options for improved press accessibility
• Enhanced Lead Screw/Tap Collet Design
• Adjustable Coolant Ring
• Unique Bill of Material Parts List for each unit(including multi-spindle units)
• One year/One Million Stroke Limited Warranty

To learn more please visit our website at www.hutchisontool.com.  The website has a library of information including CAD files, tapped hole size guide, pricing and a tapping calculator to help determine press stroke requirements and production speeds

Be Aware of Burs with Roll Tapping

The nature of rollform form tapping inherently will cause a bur.  This is due to the fact the rollform tapping forms and displaces material v. cutting out material with cut tapping.  While rollform tapping is a stronger thread than a cut thread, the burs that are produced need to be addressed.  Generally this is done but countersinking the hole so that the burs will not protrude past the top and bottom face of the material.

Another issue that comes up when rollform tapping with In-die tapping is making a clearance hole in the die for the burs from the rollform tapping operation.  If there is not a clearance hole the likely result will be the bur being pushed back into the bottom of the tapped hole.  This will result in having the go gage work to the bottom of the tapped hole and stopping at the last thread. By providing clearance in the die this issue is easily resolved. 

Having a Problem with Slivers from a Rollform Tap Operation?

Having a Problem with Slivers from a Rollform Tap Operation?

One of the biggest reasons companies choose rollform tapping is to eliminate chips during the tapping operation.  Some of the applications for rollform tapping include use in In-die tapping applications of stamped parts to keep chips out of the die or tapping of blind holes in machined parts which eliminates chips packing at the bottom of the hole.

Occasionally we will hear from customers about the formation of slivers during the rollform tapping operation.  Although these slivers are not the volume of chips resulting from a cutting tap application, these slivers can cause a problem when you are expecting a chipless tapping operation.  Generally, the cause of these slivers is the result of a hole size that is too tight.  Keep in mind that a rollform tapped hole size should be larger than a cutting tap and in addition trying to achieve greater than a 75% thread with a rollform tap can cause this sliver issue.  Please feel free to send us an e-mail to sales@hutchisontool.com if you would like us to send you a rollform hole size chart for metric and imperial size threads.

What is the Minimum Press Stroke Required for In-die Tapping

What is the Minimum Press Stroke Required for In-die Tapping?

What is the minimum press stroke required for In-die tapping?  The short answer is--it depends.  Because it depends is not a very helpful answer here are some general parameters to use when quoting or investigating new tapping projects.

The minimum press stroke required for In-die tapping is 3”.  Each tapping head generates a minimum amount of tap travel through the use of a gear ratio.  This gear ratio combined with the press stroke generates the total amount of tap travel from the open to closed position of the press stroke.  The 3” press stroke allows enough time to tap the part and allow time for feeding of the strip as well.

As the part thickness increases the more press stroke is required in order to get enough tap travel to completely tap the part.  The following are ballpark estimates of press stroke required with different part thicknesses.

Part Thickness    Minimum Press Stroke

.125” or less                            3”

.187”                              4”

.250”                              5”

.375”                              6”

.500”                              8”

What is the Proper Hole Condition for In-die Tapping?

What is the Proper Hole Condition for In-die Tapping?

We are often asked what the condition of the punched hole should be when utilizing In-die tapping.  In-die tapping does not require any special consideration in regard to punched hole condition.  However, the quality of the hole will have an affect on the quality of the thread whether you are In-die tapping or secondary tapping.

For example, when punching thicker material, it is common to see a bell mouthed condition due to material break out.  If this bell mouthed condition is not corrected it is likely that you will not receive a full thread through the entire thickness of the material.  This non full thread condition will exist in both In-die tapping and secondary tapping operations.  It is common practice to shave the punched holes in order to get a full wall thickness which in turn will lead to a complete full thread over the complete material thickness

Can Job Shops Qualify for an R & D Tax Credit

Can Job Shops Qualify for an R & D Tax Credit?

There is a misconception that the R & D Tax Credit is only for companies that are making a product line.  We all easily understand if Intel is developing a new microprocessor or Ford is developing a new hybrid engine that they are most likely using an R & D tax credit to reduce their costs.  Does this also apply for the tool & die shop that has to come up with a die design to manufacture a stamped part or CNC machine shop that has to develop a manufacturing process to mill a part to customer specifications?

The Precision Metalforming Association(PMA) hosted an interesting webinar on January 24 that highlighted that job shops indeed can and should take advantage of the R & D tax credit.  The webinar discussed several items that would qualify including any time spent to figure out methodology to manufacture dies, parts etc.  In many cases even time spent quoting could qualify for the credit. 

The speaker during the webinar was Mr. Scott Schmidt from Black Line Group.  You can contact Scott at scott@blacklinegrp.com for more information.

What is the Correct Wall Thickness of Extrusions When Tapping?

What is the Correct Wall Thickness of Extrusions When Tapping?

We are often asked what is the correct hole size for roll form taps.  This information is readily available through a variety of outlets including our website, tap manufacturer catalogs, wall charts, etc.   In addition to the correct hole size it is also important to have the correct wall thickness so the threads do not break through the extrusion walls.  So what is the correct wall thickness when tapping extruded holes?

The general rule of thumb is to have a wall thickness that is two times the pitch of the tap.  For example if a ¼-20 tap is required, each thread/pitch of a 20 thread per inch tap is .050.  If we multiply the .050 by 2 we arrive at a wall thickness of .100.  Determining wall thickness with metric taps is even more straight forward.  Just multiply the pitch of the tap by 2 and you will determine the wall thickness.  For example, an M6 x 1.0 tap would require a 2mm thick wall(1.0 x 2).