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What is MultiMaterial-Welding Technology (MM-W)?

What is MultiMaterial-Welding Blog

The next innovative process offered by Bossard is MultiMaterial-WeldingTM (MM-WTM) – an innovative fastening technique which utilizes ultrasonic vibrations to install composite fasteners in modern composite honeycomb and sandwich materials. Bossard’s MM-W technology improves assembly time and reduces the number of components required for assembly, resulting in time and in-place cost savings.

MM-W

MM-W technology uses friction generated by ultrasonic energy to permanently install rod or collar-shaped thermoplastic fasteners into a variety of composite substrates. This assembly technique creates stronger bonds, requires no pre-treatment of surfaces and produces no waste. This makes MM-W an innovative solution to use in place of more traditional fastening elements in lightweight materials.

The MM-W assembly process can be manual or automatic, resulting in a total process time under two seconds. MultiMaterial-Weldingis an efficient and quick process. If reducing assembly time in composites is a goal of your organization, Multi-Material Welding is well worth your time to consider in your manufacturing process.

For more information, check out www.bossard.com or contact our engineering department at ProvenProductivity@bossard.com.

July 12, 2019
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Why Lean Bonding Could Be the Solution You’re Looking For

Lean Bonding

Lean Bonding is an innovative new method of fastening composites and thin metal materials.  Developed by bigHead® Bonding Fasteners, a part of the Bossard Group, Lean Bonding allows users to bond fasteners to composite surfaces with incredible speed and strength, while also providing a solution that does not require drilling holes which can weaken the base composite material.

Lean Bonding allows fasteners to be permanently fixed to a suitable composite surface in as quickly as ten seconds! The process involves use of a bonding fastener equipped with a pre-applied adhesive, activated via rapid induction heating. After applying the fastener to the desired surface, the dry adhesive film rapidly cures, permanently securing the fastener.

Automated, semi-automated or manual installation methods are available, and cause no damage to the base material. Successful Lean Bonding is compatible with fiberglass, reinforced plastics, aluminum, steel and carbon fiber reinforced plastic. It is suitable for use with a variety of adhesives, fastener coatings, and sizes. Additionally, using a pre-applied adhesive ensures uniform adhesive thickness and repeatable bond quality. This makes it the ideal solution for the many technical challenges experienced when assembling composite materials that are not suited for clinching, riveting or welding.

Lean Bonding is a reliable process that offers excellent versatility for high and low production levels and can offer profound improvements in speed, quality, and cost.

Some Facts About Lean Bonding:

  • The fastener has a 24mm head, comes in M5 and M6 sizes, and in 16 or 20mm lengths
  • Wide range of OEM-approved finishes available
  • Polyurethane and epoxy based adhesive options are available

Bossard is the industry leader in fastening products and solutions, and Lean Bonding is just one reason why global market leading manufacturing companies choose Bossard as their preferred and trusted supplier for innovative fastening technologies.

To learn more about Lean Bonding and Bossard’s other effective industrial processes, check out www.bossard.com or contact us at ProvenProductivity@bossard.com.

July 05, 2019
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How to Avoid Assembly Nightmares – Part 2

Solutions to Assembly Nightmares 2

You are on a deadline. You have two weeks to produce 500 more units to meet your customer’s expectations at a rate of 50 per day so you should be in good shape. Suddenly, you have a problem. Bolts are stretching and breaking on the assembly line. What do you do now?

Your checklist should look something like the following, in order:

  1. Verify that the correct torque settings are being used – 120Nm ok
  2. Verify the torque wrench – calibration ok
  3. Check fastener property class head marking – class 10.9 ok
  4. Check for any signs of lubrication which could have gotten into the threads or under the rotating bearing surface – ok
  5. Check the core hardness of the bolts – HRC 32-39 ok
  6. Consult your fastener supplier for a joint analysis

Real Life Assembly Solutions

This exact case happened to a Bossard engineer. After checking the screws to ensure that they met specifications for hardness, the obvious recommendation was to lower the torque. But by how much? How can we ensure enough clamp load to keep the joint tight?

In this case, the design engineer had determined a minimum clamp load requirement of 30kN for a safe joint. Since the recommended torque was causing the bolts to stretch, we performed a test to determine how much torque was necessary to tighten the joint.

By performing a torque/tension test on the joint, we were able to determine that the painted surface under the flange nut had much lower friction than predicted. This caused much higher clamp loads using the recommended torque of 120Nm.

Graph comparing clamp load with a painted surface, and a bare steel surface:

Typical data from the joint analysis:

  • MA = torque
  • FV = clamp load
  • µ coef = total coefficient of friction

More testing was necessary to determine at what torque yielding would occur. In the worst case, yielding occurred at 61kN clamp force, which is higher than the minimum 30kN requirement.

The joint analysis pointed out the issue and the recommendation was to lower the torque to 110Nm to stay above the minimum clamp load and below the yield point of the screws to avoid stretching and stopping the line. Problem solved!

If you find yourself in need of joint analysis, check out Bossard’s latest Assembly Technology Expert services, especially the Expert Test Services pillar, or by contacting us at ProvenProductivity@bossard.com.

Doug Jones
Applications Engineer
djones@bossard.com

June 28, 2019
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How to Avoid Assembly Nightmares – Part 1

Solutions to Assembly Nightmares 1

Laser cutting sheet metal has some serious benefits in time savings and accuracy. It can also cause some headaches when cutting holes for direct fastener assembly.

For many years, manufacturers alike have used thread forming screws with standard machine screw threads and case-hardened special points. These screws use pre-made holes, forming their own threads into the mating material. The thickness of the material generally dictates the size of the hole needed to create the lowest driving torque and highest stripping torque which leads to the best joint performance.

Drilling or punching into mild steel creates holes for these screws. Hole size recommendations exist for each size and thickness of the material. But, when laser cutting holes, we often see the heat affected zone, which makes the surface of the material around the hole somewhat harder. If using standard hole recommendations for drilling or punching, problems can occur during assembly.

Common Assembly Problems:

  • Hard start – screws spin
  • High drive torque – gun will not seat screws
  • Breaking screws before seating

These problems usually show that the hole size is too small. With oversized holes, we often see threads stripping rather than achieving their assembly torque.

While it is difficult to provide recommended hole sizes for each material type, each thickness, and each method of preparation, performing a drive/strip torque test in a controlled environment may be the best way to ensure the best joint performance. Let’s look at an example of a test recently done by a Bossard engineer:

Plate steel provided by the customer with incrementally larger sizes of laser cut holes:

Graph of a typical test:

Graph of the average data for many hole sizes:

Typical summary data from one hole size:

By performing a joint analysis in our laboratory, we can recommend the proper hole size for your design to ensure optimal performance.

If you have interest in any type of joint analysis, check out Bossard’s latest Assembly Technology Expert services, especially the Expert Test Services pillar, or contact us at ProvenProductivity@bossard.com.

Doug Jones
Applications Engineer
djones@bossard.com

June 21, 2019
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Where to Find Hidden Cost Savings in Your Design and Assembly

Hidden Cost Savings from your Fasteners 2

Besides finding hidden cost savings in your bill of materials with Bossard’s Expert Assortment Analysis, there may also be opportunities in your design and assembly. Let’s look at an actual example found by Bossard engineers working with an electric lamp manufacturer:

Fastener Cost Breakdown 

Even though the proposed screw itself is more than three times the cost, you can save money by eliminating other fasteners and costly assembly operations as detailed below:

If you have any interest in finding hidden cost savings in your design, check out Bossard’s latest Assembly Technology Expert services, especially the Expert Walk pillar, or contact us directly at ProvenProductivity@bossard.com.

Doug Jones
Applications Engineer
djones@bossard.com

June 14, 2019
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Where to Find Hidden Cost Savings in Your Fasteners

Hidden Cost Savings from Your Fasteners

Your design has been in production for a while, and now it’s time to look into cost savings. Fasteners are such a small fraction of the total design cost, is it worth looking for savings in this area?

While it’s true that the cost of the fastener may be small, there are many hidden costs that are often overlooked when purchasing hardware. We call this Total Cost of Ownership, or TCO.

To better explain the TCO model in fastening, we use the iceberg model.

Total Cost of Fastener Ownership


On average, the fastener itself makes up only around 15% of the total costs. The remaining 85% of the costs come from development, procurement, testing, inventories, assembly, and logistics. This chain of events is adding costs to the entire fastening ecosystem.

Let’s look at an example from the Bossard Cost Savings Calculator.

If you have any interest in finding hidden cost savings in your design, check out Bossard’s latest Assembly Technology Expert services, or contact us at ProvenProductivity@bossard.com.

Doug Jones
Applications Engineer
djones@bossard.com

June 07, 2019
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3 Advantages of Using Thread Forming Screws

Thread Forming Screws

Not taking advantage of thread forming screws in your design? You may be missing out on some performance enhancements and cost savings! From plate steel and sheet metal to thermoplastics and aluminum, consider multifunctional fasteners for your next design.

What exactly are thread forming screws? Thread forming screws have the same basic thread pitch as a standard machine screw, with harder threads and different point geometry to create their own threads into an untapped hole. This eliminates tapped holes or nuts and locking features which may be necessary with conventional nut and bolt assemblies.

Self-Locking Effect

One of the big benefits of thread forming screws is the self-locking effect. Because they form their own threads, there are no gaps between male and female threads. This can lead to rotational loosening under vibration loads. This self-locking feature alone can be a good reason to switch.

Reduction of Fasteners

By eliminating nuts or costly tapping operations, as well as locking washers, adhesives or other locking elements, realizing cost savings over the entire joint is possible. Not to mention reducing the number of fasteners and operations needed for conventional assembly.

Specialty Thread Formers for Light Alloy Metals and Plastics

Many specialty type thread forms exist for assembly into light alloys such as magnesium or aluminum. They also exist for various thermoplastic materials. For some harder thermoplastics or thermoset plastics, adding a cutting feature can lessen the stress on the material. This will still create threads into the material eliminating tapping or costly threaded inserts.

For more details on thread forming screws, Bossard offers Expert Education seminars as webinars or in person at your facility, tailored to your specific questions and needs. Contact us at ProvenProductivity@bossard.com for more information.

Doug Jones
Applications Engineer
djones@bossard.com

May 31, 2019
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The Anatomy of a Fastener

The Antatomy of a Fastener

Designing fastened joints begins with a good basic knowledge of fasteners. Many engineers think they know enough about fasteners to make good decisions, but what is your level of knowledge? Here is some good information with questions at the end to test your knowledge:

Drive Styles

What is the difference between the Philips drive and the Pozidrive?

  • Applying too much torque to a Philips drive will cause it to “cam out” to avoid breaking the screw. This is beneficial for certain hand assemblies by consumers. For production assembly, it is not ideal due to tooling wear and operator fatigue if assembling by hand.
  • Pozidrive has different geometry which transfers more torque into the screw with less downforce. In a production environment, whether by hand or automated assembly, tooling will last longer and achieving a specific torque without the drive slipping is possible.

How do you tell the difference?

Pozidriv has four “tick marks” on the face of the drive for identification.

Do they use the same driver?

Property Class/Grade

How do you determine the strength of a fastener by looking at the head?

The grade or property class marks are on the head.

  • Left – property class 8.8 metric with the “8.8” stamped on the head
  • Middle – three slash marks equally spaced is imperial grade 5, which is the same strength as metric property class 8.8
  • Right – six slash marks equally spaced is imperial grade 8 which is stronger than grade 5

What does the triangle and the “ABCD” mean on the head? What does 8.8 stand for on the head of the metric fastener? What is the grade of fasteners below?

To check your answers to the questions above, contact us at ProvenProductivity@bossard.com to set-up a seminar at your facility, or keep your eyes open for our first webinar covering “The Anatomy of a Fastener”.

More than the basics, this seminar takes things to the next level by covering bolted joint principles and fastener manufacturing.

Doug Jones
Applications Engineer
djones@bossard.com

May 24, 2019
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Improve Your Plating and Coatings Strategy

Plating and Coating

Are you still using the same fastener finish that you did ten years ago? Electroplating, the “gold standard” fastener finish is NOT the same as it was five and ten years ago.

The major change to zinc electroplating over the last ten years is a switch from hexavalent chromium to trivalent which is less toxic to the environment. Some countries and specific industries have regulations banning hexavalent chrome which is forcing platers to change formulas. If you don’t need RoHS or REACH compliant fasteners, odds are your fastener finish has changed without your knowledge.

3 Reasons Why Updated Fastener Finishes Should Be Important to You

  1. If you’re still buying yellow zinc, you could be paying too much. Hexavalent chrome was yellow by default, but trivalent is clear colored. If you are getting yellow trivalent, you are paying to have a dye added to the finish which may not be necessary.
  • Your corrosion protection may be less than expected. Trivalent chromate is not “self-healing” like hexavalent. This could lead to premature white corrosion products and dissatisfied customers.
  • The coefficient of friction is different between hexavalent and trivalent chrome which could cause problems during assembly with stretching and breaking bolts using the same torque as you have always used.

What Are Alternative Finishes to the Standard Electroplated Zinc?

  • Zinc flake coating offers high corrosion protection, no HE risk and a controlled CoF to ensure more consistent joint clamp load
  • Phosphate coatings offer good shelf life protection from corrosion and provide a good base for paint
  • Epoxy electrocoat finishes offer a very nice uniform black cosmetic finish while providing good corrosion protection and no HE risk

Bossard offers Expert Education seminars as webinars or in person at your facility, tailored to your specific questions and needs. For a full seminar on Plating and Coatings, contact us at ProvenProductivity@bossard.com.

Doug Jones
Applications Engineer
djones@bossard.com

May 17, 2019
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How to Cost Efficiently Design a Bolted Joint

Designing for Cost Efficient Assembly

Often times when designing a bolted joint we try to use standard, off the shelf fasteners for the lowest cost, but the cost of the entire assembly is not considered. Take the example below found in an electric lamp:

Conventional Fastener Solution

Conventional Fastener Solution

Here we have three fasteners, a machine screw threading into a clinch nut, and incorporating an external tooth lock washer to create a good ground for a ring terminal. Seems like a pretty good, cost-efficient joint, right? But let’s look at another possible solution:

Multi-Functional Fastener Solution

Multi-Functional Fastener Solution

This solution incorporates a multi-functional thread forming screw with nibs under the head to create our needed grounding contact. The screw itself is more than three times as expensive as the machine screw above. If we look at the total cost of the assembly, we can see the savings.

Fasteners/Assembly Machine Screw Thread Forming Screw
Screw M4 x 8 $1.36/C $4.50/C
Clinch nut M4 $10.41/C n/a
Assembly of nut $17/C n/a
Mfg of pilot hole $14.88/C 14.92/C
Toothed lock washer $1.02/C n/a
Assembly of washer 4.25/C n/a
Total Cost $48.92 $19.42

The multi-functional fastener solution results in a 60% cost reduction over the conventional solution.

Bossard offers Expert Education seminars as webinars or in person at your facility, tailored to your specific questions and needs. For a full seminar on Cost Efficient Assembly, contact us at ProvenProductivity@bossard.com.

May 10, 2019
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