by ‍‍Olavi Meriläinen, Jergens guest blog

In the late 1970’s, Finnish inventor and entrepreneur Mr. Olli Kytölä developed a new clamping method for workholding. The simplicity of the idea is mind-blowing even today: instead of moving large machine vise jaws against each other, a small wedge-operated jaw is pressing the workpiece against fixed stoppers. The clamp has two jaws, so possibility to clamp one or two workpieces with one clamp is built-in.

During last 40 years, this wedge operated workholding clamp has become famous with the name OK-VISE Low-Profile Clamp. The core application has always been in CNC milling, an in early days do-it-yourself people used to build their own workholding fixtures using OK-VISE clamps and milling the remaining parts of the milling fixture themselves. ​

When we are talking about clamping the workpiece securely and safely for machining, it is important to look at various clamp models and their strengths.

The features of the machining process and the workpiece typically determine the requirements for the clamp. In most fixtures, so called force-closure is being used.

This means that typically 3 sides of the workpiece have free access to milling tool, and holding force opposing the machining forces is created by friction.
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When dealing with high forces during machining in force-closure fixtures more friction is needed between the jaw and the workpiece. This can be achieved by selecting a larger clamp, for bigger forces, or a model with enhanced grip for better friction compared to a smooth-jaw clamp.
Luckily, you can find a range of clamp options from us to securely attach even the most challenging workpieces.

In mostly used the jaw slides along the fixture base. These are called hold-down models, because the wedge design holds the jaw down and prevents the jaw from lifting up while clamping.

One way to build a workholding fixture is form-closure, where the geometry of the layout prevents the workpieces from moving.
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Another and more typical application is force-closure, where the friction between the workholding clamp and stopper jaws create a holding force that prevents the workpieces from moving. In most typical application there are 2 workholding clamps and 2 stoppers, each with the same force clamping the workpiece. When this force is multiplied by friction coefficiency µ, then we can calculate the holding force, in the abovementioned example.

H = 4 µ F
 where F is the clamping force, and friction coefficient varies. Example values when workpiece from steel is in use.
 µ = 0,15            smooth jaws
 µ = 0,28            tungsten carbide coated jaws
 µ = 0,8              serrated jaws

All in all, using a wedge operated clamp is one of the easiest and best ways to build workholding fixtures. Its operation allows you to use it for clamping multiple workpieces simultaneously or when you need a high clamping force in limited space. For more details about our low-profile clamp, we have gathered product information in our instructions.
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Stay tuned for more updates from OK-VISE as the company continues to innovate and deliver cutting-edge solutions to its customers.

by Bernard Martin

Here are some basic rules of thumb on end mill selection

Navigating the vast array of end mills available in the market can be a daunting task, especially when precision is paramount. To aid in this process, we've outlined a step-by-step guide that addresses crucial considerations for selecting the optimal end mill for your machining needs.

Step 1 – Material Identification: Identify the exact material, its condition (billet, forging, etc.), and hardness (HRC). This information directs you to the Non-Ferrous or Ferrous section of our catalog.

Step 2 – Operation Type: Determine whether you'll be roughing, finishing, or both. This guides the choice of the number of flutes and the need for chip breakers.

Step 3 – Programming Style: Choose between traditional programming, high efficiency programming (HEM), or a combination. This decision influences the number of flutes (Step 8).

Step 4 – ADOC (Axial Depth of Cut): Determine the maximum axial depth of cut the tool will experience in the part. This information helps decide the length of cut (LOC) to deploy.

Step 5 – Reach Consideration: Evaluate obstacles to clear and depths to reach. If necessary, consider a reduced necked tool to maintain length of cut while reaching deeper positions.

Step 6 – Tool Diameter Selection: Consider the machine taper, cut depth, reach, and part geometry. Keeping the tool diameter under 3/4" for 40-taper machines and adapting the diameter to programming style, cut depth, and reach requirements.  Keep in mind  what programming style (Step 3) you’re using as HEM can employ smaller diameters than you may be used to. Decide on your cut depth (Step 4). For traditional programming keep it <2xDia., for HEM keep it below 4xDia.  Decide on your total reach depth (Step 5). If needing to machine 4xDia. look at a necked tool to maintain strength and minimize deflection.

​Step 7 – Corner Radius: Determine if your part requires a corner radius. Running a corner radius on an end mill can extend its life and is especially beneficial for pre-finishing.

Step 8 – Flute Count: Consider the material and programming type to determine the ideal flute count. Non-Ferrous machining typically requires 2-3 flutes for traditional programming and 3-5 for HEM, while Ferrous machining may need 4-5 for traditional programming and 5-7 for HEM.

Step 9 – Tool Holder Selection: Always opt for the most rigid and accurate tool holder with minimal runout. Keep the Total Indicator Runout (TIR) below 0.0005 at the tip of the tool for optimum tool life and success. Consider the use of a side lock holder for specific applications.

Remember, our team at Next Gen Tooling is always available to assist you in selecting the correct product. By following these guidelines, you'll navigate the selection process with confidence, ensuring precision and efficiency in your machining operations.

Saw Thickness and Keyways:

• Challenge: When the saw thickness is less than 0.125", keyways can create stress risers and cracks.
• Solution: Washers are often used to mitigate stress, but their mounting is critical.

Washer Mounting Issues:

• Problem: Breakage, wobble, and rubbing may result from improper washer mounting.
• Solution: Washers must be clean, flat, and bur-free. Even a speck of dirt can lead to wobbling and oversize cuts.

Scoring Marks and Dirt:

• Issue: If a saw breaks, scoring marks around the hole indicate potential dirt, chips, or grit.
• Solution: Regularly inspect and clean washers, ensuring a smooth and debris-free surface.

Nut Tightness:

• Problem: Circular skid marks indicate an improperly tightened nut.
• Solution: The nut must be wrench-tight to ensure stability and prevent wobbling.

Washer Size and Equal Diameter

• Thin saws, especially, should be supported by large washers.
• Washers must have an equal diameter to prevent flexing and rubbing on one side of the saw.

Proper Nut Tightening:

• Always ensure the nut is tightly secured to prevent circular skid marks and maintain stability.

Saw Blade Teeth Breakage Causes:

• Feed Rate: Avoid excessively high feed rates to prevent stress on the teeth.
• Spindle Bearings: Regularly check and replace worn spindle bearings.
• Drive Belts and Sheaves: Tighten loose drive belts and replace worn sheaves promptly.
• Proper Tightening: Avoid improper tightening, as pauses in rotation during feed advancement can lead to breakage.
• Workpiece Indexing: Do not index the workpiece before the saw has cleared the slot.
• Workholding: Ensure the workpiece is securely held and well-supported.
• Blade Dullness: Regularly replace dull blades, as even the best tools wear out over time.

​7-Flute End Mills

• Advantages: Improved surface finish, particularly in finishing applications.
• Disadvantages: Limited chip clearance.
• Suitability: Specialized for finishing in softer materials (ISO P, M, S, H).

Looking for the perfect 5-Axis Self-Centering vise to the test against a leading competitor's vise. We've rigorously evaluated both vises across four critical performance categories to help you make an informed choice for your workholding solution.

Test Categories: 

• Jaw Lift: We examine the vise's ability to securely grip your workpiece, ensuring it won't budge during the most demanding tasks. 
• Jaw Repeatability: How consistent is the vise in holding and releasing your materials? Precision and reliability are key. 
• Jaw Changeover: Time is money in any shop. Find out which vise allows for swift jaw changes, optimizing your workflow! 
• Jaw Recentering: We test the vise's capability to reposition and recenter your workpiece quickly and accurately, saving you valuable time. 

Discover the results and decide which vise is your ideal companion for all your projects.

At Jergens, we're committed to providing top-quality manufacturing solutions, and we believe in transparency. Our goal is to help you make an informed decision when it comes to your tools, and this video is just one example of that commitment.

Don't forget to like, share, and subscribe for more informative content about our products and manufacturing innovations. Have questions or suggestions for future comparisons?

In industrial supply chain management, where the demands for efficiency and cost-effectiveness are ever-present, comes this story of innovation and strategic partnership that not only underscores the value of a keen eye for detail but also the profound impact of choosing the right solutions for seemingly mundane problems.

Tasked with overseeing the supply of everything from safety gloves to industrial vacuums and grinding discs, our distribution partner Kyle's role transcends mere product delivery. His commitment to providing not just products but value led him to identify and address a costly inefficiency in the customer's use of matting—a move that would catalyze a shift towards the adoption of Safe-Flex solutions, setting a new standard in workplace efficiency and safety.

Kyle has been with his employer, one of our top distribution partners, for a number of years and he's Integrated into his customer’s facility,

Kyle spends the bulk of his week here, fulfilling the supply chain needs for this one customer. From gloves to industrial vacuums, grinding discs to anti-fatigue mats, this facility relies on Kyle to bring not only the best products, but the best value.

​Last year, Kyle realized his customer was spending a lot of money on matting, often replacing it quicker than they would drill bits. He built a case for, and strongly suggested they take a serious look at Safe-Flex.

“They were replacing mats, in some stations, on a monthly basis. When you do the math, the savings in using a better product is right there.”

Kyle’s customer started with our Safe-Flex Workstation Kits, the simplest way for new customers to get acquainted with Safe-Flex. Safe-Flex are pre-packaged kits, that accommodate 3’ x 3′, 3’ x 5′ and 3’ x 8′ work spaces.

​The packages include all safety edging and install instructions. Options include closed and open anti-fatigue mats, as well as ESD, Antimicrobial and anti-slip grit matting solutions.

• Early feedback was positive, and they soon began customizing matting to suit their workstations throughout. Kyle recommended specific matting options for different requirements.
• Areas producing large volumes of oils required our industry leading anti- slip grit tiles.
• Areas with no oils have regular anti-fatigue mats.
• They continue to evaluate needs and bring in the appropriate zone types and sizes for those areas.

Are you spending too much money on matting? Are you mats shredded and need replacing? Give us a call! 

When it comes to broad capability, there are a few clear machine tool choices that production units and shops consider most – Five-axis, Vertical and Horizontal Machining Centers. The criterion for choosing looks different depending on what seat you sit in – from ownership to management to purchasing and finance – but from the shop floor perspective it’s all about making chips.

Getting the most out of these highly sophisticated machines involves a combination of processes, programming, tooling, workholding and human creativity. Set up between them is very different, too. Workholding on a 5-axis and Vertical Machining Centers is very straight forward – literally – since the spindle points directly to the table.

Setting up a Horizontal Machining Center (HMC) requires quite a bit more thought because the spindle points to . . . well nothing, just into the open space within the machining envelope. So, what’s the call for it?

Over the years, HMCs have evolved from single station to double, with the use of pallet changers, to pool pallets for multiple setups, and now to even include hydraulics within the pallet to load and clamp on the machine. And the evolution continues.

Today’s HMCs have great productivity characteristics including the ability to continue machining in one location while part change can take place in another. Many feature automatic tool changers and automatic pallet changers making them well-suited for uninterrupted, unmanned and continuous machining.

Configurations with multi-axis spindles also permit true five axis machining. And thanks to gravity, the chips naturally fall away from the parts.

​To meet this great potential, requires a review of several workholding issues at the outset.

1.  Angle Plate or Tombstone
First, let’s get back to the open-air orientation. All machining on an HMC starts with a workholding solution. That’s either going to be an angle plate or tombstone (column) that mounts to the HMC indexing table to provide the position and orientation of the workpiece to the spindle. The choice of this fundamental base is dependent upon the answers to remaining things to consider.

2. The Four Basics
As with all machining, all fundamental requirements must be met. Workpieces must be held securely. They must be positioned to allow access to machine all sides (ideally without having to change). Operations have to be repeatable (within tolerance). And the setup has to be designed to be easy for the operator. That includes the ability to clear chips, load, move and other ergonomic factors with the safety of that individual always being priority one.

3. What is your current need?
If you’re gearing up for the next run of parts, it’s best to begin with an SOW (Scope Of Work) including everything from what you’re looking to accomplish now, to opportunities for greater productivity, and how to best support operator skill level.

4. What is down the road?
On the heels of that, savvy engineers are mindful of future needs. Plan for it now and be ready when the demand arises. This past-the-horizon approach saves time for further utilizing technology such as incorporating robotics and other automation.

5. Opportunities for increased productivity
There are two additional productivity boosters available depending on the application. The first is the move from an angle plate to a tooling column for the ability to load a greater number of workpieces for any given setup. This is just a matter of math – a two-sided column essentially doubles that number, three-sided triples, and four-sided quadruples.

For every incremental increase, there is a corresponding decrease in overall setup time (or downtime), and conversely an increase in productivity (or uptime).

​Connections are standard T-slots or grid patterns. The second opportunity is the addition of a quick-change system that allows the entire column to be removed, changed and the next one connected, fully loaded and all in a matter of minutes or even seconds. This quick on and off works when repeatability is high and avoids having to again find zero for every changeover.

Finding the sweet spot for your shop’s productivity is very much a human effort, and a matter of choosing the best combination of man and machine. In the case of high producers like HMCs, the goal continues to be loading and changing parts faster than the machine can make them.

It is critical to properly assemble the collet and collet nut to avoid damage to the collet and make the most accurate and rigid assembly possible.

The extraction groove of the collet must be properly seated to the extraction ring of the collet nut.

If the collet extraction groove is not properly seated to the collet nut extraction ring, the collet will appear seated below the face of the nut.

This typically occurs when the collet is placed in the collet pocket of the tool holder and then the nut is threaded on the tool holder. In a correct assembly, the collet will seat at the face of the collet nut.

The image below shows a correct assembly on the left and an incorrect assembly on the right.

DO NOT tighten the collet nut if the collet appears seated below the face of the nut as this will create galling on the 30° face of the collet. Galling appear as grooves or lines in the lead face of the collet.