With a reading of 44.0, the Gardner Business Index showed that the metalworking industry in December reached virtually its highest level since July 2015. This index has been contracting at a stable rate since August, indicating that the industry may have reached a bottom in this cycle.
New orders contracted for the ninth month in a row, but they have trended up somewhat the previous five months. Production contracted for the sixth month in a row, although in November that contraction was at a slower rate. The production index has not improved as much as the new orders index during the last five months, bringing the two into better balance. The backlog index, however, contracted once again in December. Although this index improved noticeably from November, it still indicates falling capacity utilization in the months ahead. Employment contracted for the fifth straight month, although this index has improved since August. The export index contracted for the 21st month in a row, however, its rate of contraction has slowed significantly since August as the strengthening of the dollar has moderated. Supplier deliveries shortened for the third time in four months. Shorter delivery times indicate that suppliers aren’t as busy and, therefore, can more easily meet the demands of customers.
The material prices index was unchanged in December, staying at its lowest level since May 2009. Prices received have decreased since June, although they decreased at a much slower rate in December. Material prices were falling faster than prices received. Future business expectations have been steady, but somewhat low, the last four months of 2015.
Future capital spending plans have remained relatively stable for five months, and in December they were about 33 percent below the historical average. While planned spending was still contracting compared with one year earlier, the rate of contraction has decelerated since June 2015.
When should you choose rolled threads over cut threads?
Not all designers specify rolled versus cut threads when submitting part specifications, but there are good reasons to do so. Vallorbs Jewel Co. has formulated a Guide to Threads Tip Sheet explaining when you would want to choose one type over the other, and why. Considering the following points (abbreviated here) can help reduce production costs and improve strength and product performance.
- Type of material: The rule of thumb is that materials that are easy to roll are difficult to cut and vice versa. This is true in the majority of instances. The determining factor is plasticity. Materials that have good plasticity are better suited for rolling.
- Reliability: Rolling threads have an increased ability to resist fatigue. Applications with threaded parts and fasteners that are expected to operate reliability in high-pressure environments will benefit from rolled threads versus machined.
- Required part strength: As with reliability, rolled threads provide increased part strength. Parts that are rolled have a root hardness that can be as much as 20 to 30 percent greater than those that are cut.
- Chipless operation: Rolling creates burr-free knurls and eliminates chatter. A rolled thread is less likely to have any debris that flakes off the component and enters the operating environment.
- Quantity/order size: Jobs with large production volumes may lend themselves to rolling, if other qualities to do not dictate that cutting be used instead (such as material selection). Production speeds in the rolling machining process are much faster than those of cutting.
- Required tolerances: For parts that require high degrees of tolerance and limited variation from part to part, rolling offers significant advantages over cutting, ensuring that the last part produced will be as perfect and precise as the first.
- Required surface finish: Applications that require fasteners with a superior surface finish will want to select rolling over cutting. Rolled threads are burnished and work hardened by the rolling process and, as a result, have a better appearance.
- Type of thread: For applications that require very deep or coarse threads or those that require multiple threads, cutting should be the primary consideration. Rolling does not allow for the angle to be great enough to accommodate most types of multiple threads or very deep/non-precise threads.
- Type of application: The application in which the fastener or threaded part will be used may also determine if rolling or cutting is employed. Some industries, such as aircraft components or nuclear components require rolling.
Download a PDF of the full Guide to Threads Tip Sheet here. Also read this article about how Vallorbs approaches training operators on Swiss-type lathes.
Machinists aren’t likely surprised by the fact that the tool used in the long-reach application depicted in the video above features button-style inserts (courtesy of Ingersoll Cutting Tools, the video showcases the Formmaster R). Look a bit closer, however, and you’ll notice that those double-sided inserts aren’t perfectly round. Rather, the cutting edges are serrated. Employed correctly, a toothed edge can add to the strength and stability that have made button inserts so popular for heavy roughing. This January-issue article provides more information.
What is the next important step for your machining facility? How will you improve your shop’s process or prospects in the coming year?
Based on steps that other machining facilities have taken, and based on ideas we’ve recently explored in MMS, here are 10 possibilities for you to consider:
1. Automate (particularly with a robot).
Say “automation,” and the picture of a robot is probably what comes to mind. Automation is, of course, a much bigger idea than this, and there are different and simpler ways to realize a more automated process than robotic automation. That said, a robot is among the most powerful and versatile automation tools. This year, take another look at automation, and take another look at a robot in particular. Two small makers of motorcycle parts are showing how to achieve flexible responses to surges in demand through robotic automation.
2. Put performance on display.
Let the employees on the shop floor see exactly the same production metrics that the facility’s managers are watching. One way to do this is with a monitor displaying the performance in real time. Just making the metrics public and visible often leads to direct and measurable improvement in those numbers.
3. Rework your shifts.
Coordinating work across three shifts per day can be complex, and the third shift is often incomplete because it is so hard to staff. A variety of benefits can come from replacing the system of three eight-hour shifts in a five-day workweek with two 10-hour shifts in a four-day week.
4. Size up your software.
Inefficient equipment is easy to spot. Inefficiencies resulting from software limitations are harder to notice. Hardest of all to see are the inefficiencies resulting from software that the shop lacks altogether. Many machining facilities have been surprised to discover the value and impact of software improvements, particularly the adoption of ERP.
5. Look to additive manufacturing.
Additive manufacturing has the potential to transform part designs, lead times and supply chains. In metals, the capability is challenging and costly—it might not be time yet for your shop to invest in additive manufacturing. However, it is time to be aware of this technology and its emerging promise for the industries you serve.
6. Use a 3D printer.
Once you buy a 3D printer, even a small and relatively inexpensive one, it can be difficult not to use it. The freedom it gives the shop to generate customized, functional objects can provide the answer to many nagging shopfloor problems that previously went unaddressed. That was what this shop discovered.
7. Find the waste.
Non-value-added activity is pervasive in manufacturing. Arguably, there are eight major ways that manufacturing processes routinely waste effort and time. Many of the wasteful steps are invisible, because they are an unexamined part of what the shop does routinely. Walk through your shop and your processes specifically looking for these various types of waste.
8. Bring discipline to devices.
The distraction of employees’ personal devices can be a source of inefficiency. The cameras in those devices poses a security risk in the case of sensitive parts. When this shop owner banned shopfloor cellphone use, he saw measurable productivity gains and received some surprising feedback.
9. Identify the challenge that suggests the next advance.
Challenges often arise gradually. It is easy to accept some slowly growing difficulty as just a chronic problem that has become a bit worse over time. But that growing difficulty might be a sea change. A medical component maker provides a useful illustration in identifying challenges and changing practices to adapt.
A group of independent small shops working together can achieve many of the advantages of a large manufacturer. That is what this coalition of shops discovered, an active and mutually beneficial alliance of shops that even includes some competitors.
11. Bonus idea: Keep reading.
All the links within the 10 ideas above connect to articles and resources published in 2015. Make it a regular habit of reading Modern Machine Shop throughout the coming year to find more ideas like these. Subscribe here or renew your subscription.
Schaeffler’s Machine 4.0 concept features a variety of sensors embedded in the bearing supports of a machining center. (Photo courtesy of Schaeffler group.)
A new generation of sensors is here and it is ushering in the next industrial revolution. In the interconnected world of the Industrial Internet Things, some of the most important data about connected machines and equipment will come from sensors the likes of which we have not seen before. Here are some representative examples.
Sensors in critical machine bearings. Because bearings and bearing supports are present in all of the moving parts of a machine tool that are critical to the machine’s functionality and machining accuracy, the condition of these components greatly influences the most vital performance characteristics of the machine tool. Detecting and measuring variables related to the condition of these bearings is a real boost to machine monitoring capability. Read how Schaeffler, a leading German supplier of industrial bearings, has embedded digital sensors in a machine tool to support Industry 4.0 concepts.
A sensory toolholder measures machining forces in real-time. The Spike toolholder from Pro-Micron USA detects and measures the forces in torque occurring while a machining operation is underway. Strain gages embedded in the holder are connected to a transmitter that broadcasts the data wirelessly to a receiver and attached computer for analysis. We first saw this innovation at Westec 2015.
Detecting chips in a milling spindle. Grob’s chip-in-spindle detection system consists of a rotor and stator assembly that is integrated within the face of the spindle. Sensors in these components detect stresses that may indicate chip interference that occurs during an automatic tool change. Automatic monitoring of tool clamping to detect chip interference between the toolholder and the spindle has multiple benefits. It increases process stability; protects cutting tools and the machine; helps optimize machining processes; makes automatic tool changes more reliable; and prevents runout discrepancies that might result in machining errors or defective parts.
A low cost way of monitoring the temperature of machine tool components. As a summer project at the Advanced Manufacturing Resource Center in the UK, a chemical engineering student from the University of Sheffield developed the software and hardware for a wireless sensor network that can provide a drop-in solution for monitoring the temperature of multiple machine tools. His system uses the popular Arduino and Raspberry Pi platforms alongside inexpensive ZigBee radios which together provide a compact and low-cost solution for wireless data acquisition. Read about the project in AMRC's Quarterly Journal here. (Here is a PDF of the article if you are having trouble opening it in Chrome.)
Also, here's more about the importance of emerging sensor technology in the Industrial Internet of Things and Industry 4.0 (the fourth Industrial Revolution).