Related Glossary Terms
- computer numerical control ( CNC)
computer numerical control ( CNC)
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.
- machining center
CNC machine tool capable of drilling, reaming, tapping, milling and boring. Normally comes with an automatic toolchanger. See automatic toolchanger.
- metalcutting ( material cutting)
metalcutting ( material cutting)
Any machining process used to part metal or other material or give a workpiece a new configuration. Conventionally applies to machining operations in which a cutting tool mechanically removes material in the form of chips; applies to any process in which metal or material is removed to create new shapes. See metalforming.
Reduction or removal of workhardening effects, without motion of large-angle grain boundaries.
- sawing machine ( saw)
sawing machine ( saw)
Machine designed to use a serrated-tooth blade to cut metal or other material. Comes in a wide variety of styles but takes one of four basic forms: hacksaw (a simple, rugged machine that uses a reciprocating motion to part metal or other material); cold or circular saw (powers a circular blade that cuts structural materials); bandsaw (runs an endless band; the two basic types are cutoff and contour band machines, which cut intricate contours and shapes); and abrasive cutoff saw (similar in appearance to the cold saw, but uses an abrasive disc that rotates at high speeds rather than a blade with serrated teeth).
Cylindrical tool that cuts internal threads and has flutes to remove chips and carry tapping fluid to the point of cut. Normally used on a drill press or tapping machine but also may be operated manually. See tapping.
Machining operation in which a tap, with teeth on its periphery, cuts internal threads in a predrilled hole having a smaller diameter than the tap diameter. Threads are formed by a combined rotary and axial-relative motion between tap and workpiece. See tap.
Over the last five years, ozone-depleting chemicals have been gradually withdrawn from use. Here, a fluid-products manufacturer examines the impact of this phase-out on the metalcutting industry.
Almost five years have passed since Congress enacted the amendment to the Clean Air Act of 1970 demanding the phase-out of Class I ozone-depleting chemicals (ODCs). As the enforcement agency for environmental decisions handed down by Congress, the Environmental Protection Agency (EPA) is implementing the total phase-out of the production and import of Class I chemicals by December 31, 1995. Many companies have invested a large amount of time and resources preparing for the ban. With the deadline almost upon us, let’s see how close we, as an industry, are to compliance.
The EPA identified 1,1,1-trichloroethane (methyl chloroform)—commonly found in many types of industrial tapping, cleaning, machining, and other metalcutting fluids—as a substance that causes chemical reactions that split O3 molecules in the earth’s ozone layer. Other Class I ODCs include chlorofluorocarbons (CFCs), polybrominated biphenyls (PBBs), and carbon tetrachloride.
To begin limiting the production and import of ODCs, the Internal Revenue Service (IRS) issued an escalated tax schedule on ODCs in 1992, starting at $1.37/lb. and reaching $5.35/lb. in 1995. Thus, manufacturers were forced to significantly raise their prices, and customers had to decide whether to pay or find alternatives.
Although the EPA may permit the use of ODCs under special circumstances, products containing 1,1,1-trichloroethane will be even more difficult and costly to obtain after December 31, 1995. This has caused some concern in the metalcutting industry, because users have become accustomed to the convenience, economy, and high performance of products containing 1,1,1-trichloroethane. For years, 1,1,1-trichloroethane was used in metalcutting fluids because it cools by evaporation, leaves no residue, is nonflammable, and may be used as a carrier for extreme-pressure additives. However, as these fluids become harder to find and more expensive, replacement products will be easier to obtain and more affordable.
Following the 1992 escalated tax schedule, all products manufactured with Class I chemicals on or after May 15, 1993, were required to contain a highly visible warning label naming the ODC and explaining its public-health and environmental ramifications. After a brief delay, enforcement of the regulation began in November 1993.
Before the use of mandatory labeling, many end users were simply not aware that some fluid products contained hazardous materials. ITW Fluid Products Group conducted a survey at the 1992 International Manufacturing Technology Show to discover end-users’ awareness of the EPA’s ruling against the production of fluids that contain 1,1,1-trichloroethane and other ODCs. Of the 150 people surveyed—including engineers, first-line supervisors, machine operators, and top-level management—nearly half (48%) had little or no knowledge of the 1995 ban.
The enactment of warning labels dramatically increased the industry’s attentiveness to the overall ban. As a result, manufacturers were put under greater pressure by distributors and end users to provide alternative products.
“Our company saw the ban coming early on and took a proactive stance,” explains Mark Semelman, product manager for MSC Industrial Supply Co., a large catalog distributor based out of Long Island, NY. “Our customers told us that they didn’t want any products containing Class I ODCs such as 1,1,1-trichloroethane. So about three years ago, we went to our vendors and told them we wanted to eliminate any products manufactured with Class I chemicals from our sales list by the publication of our next catalog.”
Like many distributors, MSC Industrial Supply asked manufacturers to determine when alternatives would be available for their products that contained Class I chemicals, or to produce proof that their current product line didn’t contain 1,1,1-trichloroethane or other Class I ODCs. “Most manufacturers offered alternative products,” adds Semelman. “We dropped any products still containing ODCs.”
Beginning in 1994, manufacturers were faced with further challenges—limiting production of ODCs to 60% of 1989 levels. This ruling by the EPA was another step toward completion of the 1995 phase-out. It was a wake-up call for those businesses that hadn’t switched to alternative products.
Although many of their customers were accustomed to the convenience and high performance of products containing ODCs, the ban forced manufacturers to update some of their products. For most manufacturers and distributors, this was good news, because customers that had been buying the same 1,1,1-trichloroethane products for years out of habit were now looking at alternatives.
While looking for alternatives, many consumers ask manufacturers to send a representative who can demonstrate replacement products on their machines. John Stier, director of purchasing for Production Tool Supply, an industrial distributor located in Warren, MI, notes that some end users are going as far as contacting chemists to receive more information on the components of the alternatives. “I’ve noticed a large number of requests for samples or orders for small quantities of these items,” adds Stier.
According to Stuart Silbert, president of Harbor Tool Supply Co., an industrial distributor based in Westwood, MA, “Since eliminating the ODCs from our product line, we’ve had zero complaints from customers regarding replacement products. Overall, the outcome has been beneficial for our customers and for us.”
Time for Change
Throughout the industry’s search for alternatives, manufacturers have been challenged to find replacement products that equaled or exceeded the performance levels customers had become accustomed to and that met EPA standards. The result was extensive research, production, and testing by manufacturers to develop ozone-friendly products.
“The ban forced manufacturers to take a closer look at how their products were produced and used,” explains Stier. “Initially, there was a scramble by our vendors to move forward in areas that had not been explored. The end result was products that are environmentally compatible. Today, manufacturers are continually improving and reformulating their replacement products.”
Figure 1: Ozone-friendly products such as this tapping lubricant paste meet EPA regulations and are safe for workers.
For example, one manufacturer that produced tapping fluid products containing Class I chemicals developed a family of tapping fluids, composed of environmentally compatible ingredients, that met EPA regulations and posed no health risks to workers. In addition, the products were easier to use than those containing 1,1,1-trichloroethane, because they were developed in a wider variety of forms (including liquid, stick, paste, and aerosol) to accommodate the many different application requirements of end users (Figure 1).
When independently tested against the leading 1,1,1-trichloroethane-based tapping fluid, the replacement product offered the same level of high performance without negatively affecting the environment, the ozone, or the user’s safety. Furthermore, the replacement fluid produced no smell and no chip sticking, and it was less smoky and oily than the 1,1,1-trichloroethane-based fluid.
The rigorous test involved tapping 1,008 holes in 4140 steel, heat-treated to Rc 30. A Haas VF1 CNC machining center with a rigid tap set was used to run the test. The 3/8-16 high-speed, spiral-point, bright-finish tap was run at 35 sfm. The results of this test sent a reinforcing message to the company’s customers that they could feel safe using an alternative product without sacrificing performance.
SNAP Offers Help
To help end users identify approved replacement products, the EPA established the Significant New Alternatives Policy (SNAP) program on March 18, 1994. SNAP evaluates chemicals that companies manufacture to replace ozone-depleting substances and determines whether the new products are safer than the ODCs they’re replacing.
“The SNAP program is a good starting point for companies interested in information on approved alternative products,” explains Nina Bonnelycke, solvents substitute analyst for the EPA’s Stratospheric Protection Division, Washington, DC.
According to Drusilla Hufford, acting director of the Stratospheric Protection Division, “Of the more than 300 alternative products submitted for review under the SNAP program, the great majority are acceptable. Generally, replacement products that are unacceptable are flammable or ozone-depleting.”
Recent reports by scientists with the National Oceanic and Atmospheric Administration, Aeronomy Laboratory, Boulder, CO, have revealed that the atmospheric abundance of 1,1,1-trichloroethane is, in fact, decreasing as a direct result of the 1990 amendment to the Clean Air Act and the Montreal Protocol, which controls the production and consumption of ODCs internationally.
These findings, based on data collected from surface-level monitoring stations, indicate that methyl chloroform has shown a “distinct decrease in atmospheric abundance.” The reports also conclude that if conditions remain the same, the decrease in atmospheric chlorine—caused by ODCs—should result in a slow recovery in stratospheric ozone levels.
With the EPA’s total phase-out just weeks away, reports like these take on a greater meaning for the metalcutting industry. The time and money invested by manufacturers to produce approved replacement products appears justified. Distributors feel positive about their product lines. And end users may be more convinced than ever before that the ban was effective and necessary. Overall, everyone is a winner.
About the Author
Norm Semple is a sales manager for SafeTap products at ITW Fluid Products Group, Norcross, GA.