Manufacturers of professional quality stainless steel hand tools designed for use in critical production, sterile, Cleanroom, or corrosive environments

The questions above are intended to serve as general guidelines for understanding some of the materials and procedures used in the production of Steritool stainless steel tools. They represent either actual questions commonly asked over the years by Steritool customers or questions that we have devised as a very general introduction on topics that pertain to our products. Much has been written about these topics and detailed information is available from a variety of resources.

We welcome submission of your own question. Please use the form below and let us know what's on your mind.

What is a critical environment application?
A critical environment is one that has zero or a predetermined tolerance level for particulate and contamination.                                                             

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Why use stainless steel for tools in critical environments?
In a critical environment it is usual that the tools would be sterilized frequently. The stainless steel and finishing processes that are used for Steritool products can be sterilized through thousands of cycles without deterioration.                                                               

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What are some examples of a critical environment?
Sterile production areas such as laboratories in biotech and biomedical facilities, cleanrooms in pharmaceutical and nutrient production, nuclear industry, silicone wafer production, food processing and wet process facilities. Critical environments exist in an ever changing list of industries.   

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What specifications are used in the production of Steritool hand tools?
Steritool uses the same exacting standards that are used for dental and surgical instruments. This applies to the material as well as the finishing processes                        

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Over what range of Ph values can Steritool hand tools be used?
The range is very wide, from acid to alkali. For extreme applications, it is advised to make preliminary tests to determine suitability for the application.                           

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What is stainless steel?
Stainless steel is a range of alloys, the elements of which are chromium, nickel, iron, manganese, silicon, phosphorus, copper, molybdenum, titanium, columbium, and tantalum. Varying the proportions changes the characteristics of the resultant alloy. For a more detailed analysis of commonly used stainless alloys, see our page on classification of stainless steel.                                    

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What gives stainless steel its corrosion resistance?
Stainless steel is a low carbon steel which contains chromium at 10% or more by weight. The addition of chromium gives the steel its corrosion resistant properties by allowing the formation of an invisible chromium-oxide film on its surface. If oxygen is present, even in small quantities, this film self-repairs if damaged mechanically or chemically. Corrosion resistance of stainless steel is enhanced by increased chromium content and the addition of other elements such as molybdenum, nickel, and nitrogen.                                                                                                                 

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How many different types of stainless steel are there?
There are thousands of alloys possible- in reality there are approximately twenty types of stainless steel in common use.                                                                                    

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How are stainless steels categorized?
There are four main classifications: Austenitic (300 series), Martensitic (400 series), Precipitation Hardenable (17-4PH, 455), and Ferritic (430, 443).                             

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What is the difference between these groups?
The main difference is whether and how they can be hardened by heat treatment. For a full technical description of stainless steels, refer to Carpenter Technology Corp.         

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What types of stainless steel does Steritool use for their range of hand tools?
We use alloys from all four categories. The alloy is selected to match the physical characteristics required for the proper functionality of the particular hand tool.                 

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Is stainless steel magnetic?
Each alloy exhibits a different level of magnetic characteristics. All Austenitic (304, 316, 316L) stainless steels are non-magnetic in the fully austenitic condition as occurs in well annealed alloys. All of the other alloys are magnetic in varying degrees.

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What hardness scale is used to measure the hardness of stainless steels?
The most commonly used is the Rockwell "C" scale; it is abbreviated to "HRC".

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Is stainless steel softer than the carbon steel used in "regular" hand tools?
Our Carpenter Technology 465 alloy can reach HRC 60. By comparison, carbon steel can reach HRC 62. The difference is about 3%.

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In what quantities are stainless steel hand tools produced?
The stainless steel hand tool market is a "niche" market. The tools are produced in small quantities. Typically, production runs number about one thousand pieces or fewer, with custom tools being produced in lots as small as ten pieces.

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How much does stainless steel raw material cost?
It ranges from $4.00/lb. for older, less complex alloys up to $20/lb. for the more recently developed high tech alloys.

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How does this compare to the cost of carbon steel?
Carbon steel is typically one-tenth the cost of stainless steel.

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How many times can I sterilize a regular carbon steel hand tool?
Usually less than twenty autoclave cycles. Beyond this the chrome plating will begin to flake off and pitting of the surface will begin-with ferrous contamination of the process beginning. 

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What is ferrous contamination?
This is the process where ferrous (iron) particles transfer to the surface of a product manufactured from stainless steel. It can happen during the manufacturing process or by using a carbon steel tool on stainless fasteners. In due course the stainless will begin to rust where it has been exposed to the iron particles.

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Through how many cycles can I sterilize a Steritool hand tool?
Through thousands of cycles, with zero particulate generation or process contamination.

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What does cGMP mean? What is process validation?
cGMP stands for current Good Manufacturing Practice. It is a set of guidelines for manufacturers in the Life Sciences and other industries that assist in maintaining compliance with FDA regulations. Process validation is part of maintaining cGMP. It means maintaining- and validating by testing procedures- a quantifiable level of sterility and contamination control specific to the requirements of a particular industry. By validating a manufacturing process, Quality Control personnel are able to isolate and evaluate sources of process contamination when they occur.

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How can Steritool help me maintain cGMP?
Stainless steel is an homogenous material, which means there is no plating or coatings to peel or chip. This minimizes the risk of contamination by particulate generation. Stainless steel is compatible with laboratory equipment, eliminating ferrous contamination.

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Are Steritool hand tools cost effective?
Yes, very much so. With a long service life, the return on investment (ROI) is in the range of one hundred to two hundred times that of an equivalent carbon steel hand tool. This, combined with their uselfulness in helping maintain cGMP make Steritool hand tools an intelligent investment.

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Are stainless steel hand tools compatible with my stainless steel process equipment?
Yes. Using stainless steel tools with stainless steel process equipment means total material compatibility. The resultant zero level of ferrous contamination greatly reduces the necessity for periodic passivation of fasteners and other components.

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How should I store my Steritool hand tools?
Steritool hand tools should be stored in stainless steel tool boxes or trays. Alternatively, autoclaveable plastic trays can be used. It is essential that stainless steel tools are not stored or allowed to come in contact with carbon steel tools, equipment, tool boxes, or trays. If they do, ferrous contamination occur and passivation will be necessary.

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What is passivation?
Passivation is the removal of the free iron from the surface of stainless steel. There are a number of different passivation processes, including the newer citric acid process which is more environmentally friendly than the older nitric acid methods. The removal of the free iron facilitates the interaction of the chromium in the steel with oxygen, which produces the formation of a non-reactive, i.e. passive, oxide film layer. This thin, invisible layer protects the material against further corrosion by it's ability to self repair- if the metal is scratched and the passive film is disrupted, more oxide will form and cover the exposed surface. For deep scratches, the tool can passivated again.

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Is it normal to have to passivate stainless steel items over the course of their useful life?
Yes, and the frequency depends on the process. If "rouging" is noticed on the tool, fastener, or process equipment, passivation will be required to remove the free iron and renew passive layer.

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