The prices of all raw materials that we track rose as follows over the past year:
Aluminum: Up 23% from July 2009.
Brass: Up 28% from July 2009.
Copper: Up 17% from July 2009.
Nickel: Up 70% from July 2009.
Stainless: Up 37% from July 2009.
Steel, Busheling: Up 51% from July 2009.
China Coke, Up 3% from July 2009.
You can download the August Material Impacts report free here
We track these items as they indicate the direction that we wll be paying for our raw materials in our precision machining shops, Steel, Aluminum, Brass and Stainless barstock. These items are critical to the manufacture of those materials.
When present in substantial amounts, Nickel provides a number of benefits to steel.
Nickel’s main contribution to steels is making them more forgiving of heat treatment variations. Think of it as the Heat Treater’s Friend.
Nickel lowers the critical temperatures, while widening the the temperature range for effective quenching and tempering. Nickel also retards the decomposiition of Austenite. Since nickel doesn’t form carbides, it doesn’t complicate the reheating for austenitizing process either. Nickel contributes to an easier and more likely to be successful heat treatment.
Here are 5 Contributions Nickel makes to our alloy steel parts:
Improved toughness (especially at low temperatures!)
Simplified and more economical heat treatment (Money saved!)
Increased hardenability (depth of hardness achievable)
Less distortion during quenching (more good parts after Q&T!)
Improved corrosion resistance (See this link– 2.1 % of GDP lost to corrosion!)
In addition to its appearance in the credits for 43XX, 46XX, and 86XX alloy steel grades, Nickel is a major component of Stainless Steels, Invar, Monel, and Inconel.
Machinist hint: When you see Nickel as a major ingredient in steel, avoid tool dwell and light cuts. Nickel contributes to a material’s workhardening ability. Photo credit.
Prices of raw materials used to make precision machined products are up substantially, ranging from 44% to 114% from March 2009- March 2010 for 6 of the 7 materials we track.
Low inventories, increasing demand, idled production facilities, are among the factors involved here in North America.
As are the historic iron ore agreement and continued high demand in China.
Fuel price increases also impact freight, which is an important factor in our business.
We will not be shocked to see monies paid for steel in May to be $80 per ton higher than they were in April based on already announced price increases and the current price on #1 busheling which determines surcharges.
Read more and download the .pdf report here. Photocredit.
11 industries reported expansion in February. The Precision Machined Products Industry, a sub industry of Fabricated Metals, serves 7 of these industries showing the greatest recovery.
Here are the sectors that reported expansion that precision machining serves:
Computer & Electronic Products;
Appliances & Components;
Fabricated Metal Products;
Economic activity in the manufacturing sector expanded in February for the seventh consecutive month, and the overall economy grew for the 10th consecutive month, say the nation’s supply executives in the latest Manufacturing ISM Report On Business®.
The PMI index for February was 56.5 down 1.9 percentage points from January. Because the PMI is above 50, the manufacturing economy is expanding.
According to ISM steel, stainless steel, and aluminum are increasing in price.
Anecdotal data from our conversations with members confirms the ISM numbers, and points out that the metals named above are both more expensive and in short supply.
You know business is improving when they are out of plain vanilla. Photocredit.
Surface finish issues are especially critical in aerospace and medical applications. Chips recontacting the work and high or unstable Built Up Edge (BUE) are the usual suspects of poor surface finish on machined parts, regardless of material. There can be other factors, such as a poorly maintained machine or exhausted metalworking fluids, but these are seldom the case when “the last job on this machine ran just fine.”
Here are our 5 tips that you can address on the machine to make poor surface finish go away: 1) Increase the speed SFM (especially on Carbide!). This will help reduce BUE. 2) Reduce the feed per revolution (IPR- inch per revolution). This will help reduce the flank wear. 3) Increase the top rake angle. 4) Add a chip breaker / chip curler. 5) Increase tool nose radius.
We have seen increasing speed to be especially helpful on aerospace and medical machining jobs on stainless steel. Increasing speed is also important when using carbide- carbide likes speed.
If you can see that the chip is recontacting the workpiece, then address your chip control issues first. Chip control is the first place to start. Adding chip control geometry on the tool is probably the easiest change on non CNC machines. Modifying the cam to break the chip should also be considered. On CNC’s, adding chip breaks into the program is also an easy adjustment. These are especially effective if the workpiece is a gummy material. Built Up Edge (BUE) is impacted by three primary factors: material chemistry (which you can’t change- you already have the material); surface footage (slower speed means hot chip is in contact with tool longer, creating higher BUE); and tool geometry (the point is to slice or cut, not rub off the material).
Of course, you should make sure that your setup is rigid, your tooling properly seated, your coolant lines are delivering plenty of coolant to the tool/work interface, etc., etc.. But these 5 tips are ‘Tools You Can Use’ to improve the surface finish on your problem jobs, including stainless and other aerospace and medical materials.