Producing components to tight tolerances is only the beginning of what precision machining means . In our view, a precision job isn't done until it is precisely in line with customer expectations for reliable delivery, component quality and world class cost effectiveness.
None of these outcomes can be successfully achieved without state-of-the-art Equipment.
SUBSAFE is a quality assurance program of the United States Navy assigned to maintain the safety of the nuclear submarine fleet; specifically, to provide maximum reasonable assurance that subs' hulls will stay watertight, and that they can recover from unanticipated flooding.
SUBSAFE covers all systems exposed to sea pressure or critical to flooding recovery. All work done and all materials used on those systems are tightly controlled to ensure the material used in their assembly as well as the methods of assembly, maintenance, and testing are correct. They require certification with traceable quality evidence. These measures increase the cost of submarine construction and maintenance.
SUBSAFE addresses only flooding; mission assurance is not a concern, simply a side benefit. Other safety programs and organizations regulate such things as fire safety, weapons systems safety, and nuclear reactor systems safety.
Machining for the Nuclear Industry under 10-CFR-50 Appendix B & Part 21 Regulations .
Large Machined Shafts and Rolls
Precision manufacturing of large shafting and rolls (up to 45" in diameter to 410" in length, or up to 3 tons) commonly used for paper and pulp production, power generation, mining, pharmaceutical/biotech, oil drilling, and turbomachinery. These and other shafting needs typically include large drive shafts, impeller shafts (including electropolished shafts), journals, rolls, and pump shafts. Also shafting requirements for keys, lock nuts, hardcoat plating, electropolishing, and stainless steel, brass and ceramic sleeves. Common shaft materials include 4340 alloy annealed and heat treated, 1141, 1018, and 316 SST.
Large Capacity Milling
Gear Cutting & Hobbing:
The machine forms the gear via a generating process by rotating the gear blank and the cutter (called a hob) at the same time with a fixed gearing ratio between hob and blank. The hob has a profile given in cross-section by the fundamental rack for the gear tooth profile and is in the form of a helix so that the sides of the teeth on the hob generate the curve on the gear. The helix has a number of cuts parallel to the axis to form the cutting teeth and the profile is suitably relieved to provide cutting clearance.
For a tooth profile which is a theoretical involute, the fundamental rack is straight-sided, with sides inclined at the pressure angle of the tooth form, with flat top and bottom. The necessary addendum correction to allow the use of small-numbered pinions can either be obtained by suitable modification of this rack to a cycloidal form at the tips, or by hobbing at other than the theoretical pitch circle diameter. Since the gear ratio between hob and blank is fixed, the resulting gear will have the correct pitch on the pitch circle, but the tooth thickness will not be equal to the space width.
Hobbing is invariably used to produce throated worm wheels, but it is not possible to cut all useful tooth profiles in this way; if any portion of the hob profile is perpendicular to the axis then it will have no cutting clearance generated by the usual backing off process, and it will not cut well. The NHS Swiss tooth standards give rise to such problems. Such small gears normally must be milled instead.
Flame hardening is an oxy-acetylene heating process used to produce a hard case on the surface of a wide range of mechanical components. Burning fuel gas impinges directly on the surface to be hardened. When the surface reaches the austenizing temperature, the part is immediately quenched to produce a locally hardened surface.
Typical flame hardening applications include blades for turbine engines, gears for paper machinery, rolls for the printing and metalworking industries, cams for packaging machinery, machine tool beds, and automotive components.
Cost reductions occur as a result of the reduced distortion, allowance for straightening, and elimination of operations associated with flame hardening.
The use of flow controls, infra-red temperature sensors, and automated parts feeding insures conformance to your engineering specifications. Magnetic Particle Inspection is performed on a sample of all lots processed. Documentation is maintained for each order for a period of five years.
In the induction heating phenomena, a high frequency electric current is passed through a conducting coil surrounding the part to be heated. The electromagnetic energy created induces a current to flow on the surface of the part to be heated. By controlling the power, time, and temperature we are able to locally heat a wide range of components producing the correct metallurgical results to meet manufacturing requirements.
Induction heating is energy efficient and environmentally friendly. It also reduces distortion and improves the desired mechanical properties. Typical applications include tempering, annealing, hardening, brazing, and shrink fitting.
The use of microprocessor controls and infrared temperature sensing enables the heating cycle to be monitored for 100% of your components. A family of automated parts feeding equipment has been developed that allows the most efficient heating possible. New coil designs and the use of intensifiers allows for multiple part heating to increase productivity and reduce costs.
For each part inspected, there is documentation of the process. The heating time, part temperature, quench temperature, and voltage are recorded to insure the accuracy and repeatability of the operation. A sample of each lot is then Magnetic Particle Inspected to insure the integrity of the part. Laboratory facilities are available for metallographic studies.
Automated Hardening Process:
In an effort to enhance the productivity and control of the localized heat-treating process a wide range of automated parts feeding equipment has been integrated with optical infrared pyrometry. The PLC provides control of the sensing, location and motion for feeding and locating parts. The pyrometer provides temperature control of the parts during processing.
Typical applications of these technologies have allowed the ability to harden multiple parts in one operation. Flame hardening of mechanical components has been automated. Temperatures of each part heated can be controlled within a few degrees. Induction stress relieving cycles have been as short as 10 seconds and have reached 12 hours depending on the alloy processed. There is also the capacity to provide inert gas atmospheres to these operations. Charts can be developed for the process of each stress relieved item processed.
Computerized records provide the basis for certification as required by the customer.
TM Limited provides you with precision machining on most metals, as well as machining on intricate plastic parts.
Whatever your machining needs ... if you need the job done, you need it done right, you need it done quickly and at a competitive price, call us today at 508.946.4533 or e-mail us at email@example.com