Alloy: A metal containing additions of other metallic or non-metallic elements to enhance its metallic properties. Commonly used term to denote materials with relatively high amount of alloying elements.
Anneal: A controlled heat treat process used to obtain specific material properties. (Usually to soften the material).
As Forged: The condition of a forging as it comes out of the finisher cavity without any subsequent operations.
Bar: A section of hot (or cold) rolled steel rolled from a billet to a form, (such as round, square, etc.) with a cross-sectional area of less than 16 sq. in., and whose width or greatest distance between parallel faces is 3/8" or more.
Billet: A semi-finished, cogged, hot-rolled, or continuous-cast metal product of uniform section, usually rectangular with radiused corners. Billets are relatively larger than bars.
Black Oxide: The industrial coating which is applied to Martin non-chromed hand tools.
Blast Cleaning: A process for cleaning or finishing metal objects with a shower of high velocity abrasive particles, (beads, grit, sand or shot).
Bloom: A semi-finished product of square, rectangular, or even round cross section, hot rolled or forged. For steel, no invariable rule prevails for the distinguishing between blooms and billets; the terms are frequently used interchangeably.
Brinell Hardness: The hardness of a metal or part, as represented by the number obtained from the ratio between; the load applied on, and, the spherical area of the impression made by, a steel ball forced into the surface of the material being tested. (Expressed as BHN) Also, a standard table scale used to measure relative hardness of a metal or part as compared to Rockwell "C" or "B" Scale hardness.
Broach: The process used to put box openings into various hand tools. (Martin uses a Hot Broach method on all openings over 2". All other smaller openings are obtained from the use of a Pull Broach). Also the term used to describe the process of generating these openings.
Carbon Steel: Steel that derives its properties mainly from the addition of carbon, without substantial amounts of other alloying elements.
Cavity: The machined recess (impression) in a die that gives the forging its shape.
Charpy Impact Test: An impact test in which a specially V-notched specimen is broken by the impact of a falling pendulum. The energy absorbed in fracture is a measure of the impact strength or "notch toughness" of the sample.
Check: A crack in a die impression, generally due to forging pressure and/or excessive die temperature.
Coining: The process of lightly deforming all or some portion of a forged part to obtain closer tolerances, smoother surfaces or, to eliminate draft.
Cleaning: The process of removing scale, oxides, or lubricant – acquired during heating for forging or heat treating – from the surface of the forging.
Closed Die Forging: The shaping of hot metal completely within the walls or cavities of two dies that come together to enclose the workpiece on all sides (and does not allow for flow of excess material).
Closed Impression Die: The type of die that is used for the closed impression die forging process. Each consists of an upper (moving) and lower (stationary) half which has an impression which has been sunk to produce the required part when the dies are closed in a forging hammer.
Closed Impression Die Forging: The process of shaping of hot metal by compression completely within the cavities of two dies that enclose the work piece on all sides and allows for the controlled flow of the excess material or flash that is generated. (Also referred to as Impression Die Forging). (This is the process used at Martin Tool & Forge.)
Coining Press: The type of machine that is used to hold and cycle the coining dies in the coining process. This process is typically used for straightening and/or obtaining an improved finish or closer tolerances over the "as forged" part.
Cold Shut: Also known as a lap or fold. A defect such as a lap that forms whenever metal folds over itself in the forging process. This can occur where vertical and horizontal surfaces intersect.
Dies (die blocks): The metal blocks into which forging impression cavities are machined and from which forgings are produced.
Die Match: The alignment (or allowable misalignment) of the upper (moving) and the lower (stationary) dies installed in a forging hammer. An allowance for misalignment (or mismatch) is included in normal forging tolerances.
Die Sinking: The process of machining impression cavities in die blocks. (Martin can perform Conventional, EDM or Direct die sinking)
Draft: The required taper on the sides of a forging that is necessary for removal of the workpiece form the dies, also applies to the die impression.
Draft Angle: The angle of taper, expressed in degrees (usually 5 - 7), given to the sides of the forging and the side walls of the of the die impression(s).
Drop Forge: The process of shaping hot metal (producing a Drop Forging) between dies in a drop hammer.
Drop Hammer: The term generally applied to forging hammers wherein energy for forging is provided by gravity, steam or compressed air. (Martin hammers are pneumatically operated).
Dye Penetrant Testing: Inspection procedures for detecting surface irregularities using penetrating liquids containing dyes or fluorescent substances.
Finish Allowance: The amount of stock left on the surface of a forging for machining requirements. Also called "machining allowance" of "Forging Envelope".
Forging: The process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls or other related forming equipment. (Also used to describe the part which is produced from these processes.
Forging Envelope: (See Finish Allowance)
Flash: The deformed, unusable metal which remains around the work after the forging process and prior to trimming.
Flash Extension: That portion of flash remaining on the forged part after trimming. Usually included in normal forging tolerances.
Furnace: The equipment used to elevate the temperature of the steel stock to that temperature which is necessary for the applicable forging process. (Martin utilizes both gas fired and electric induction furnaces.)
Grind: The process of removing specified deformations from, or providing a smoother finish to the workpiece or Hand Tool. Hand tool grinding is usually done with stationary belt grinders utilizing appropriate belts and speeds for the desired finish. (Martin utilizes RYMAN and BADER grinders in our hand tool finishing processes.)
Hammer: (See Drop Hammer)
Heading: The upsetting of wire, rod or bar stock in dies to form parts that usually contain portions that are greater in cross-sectional area than the original wire, rod or bar.
Heat Treat: A sequence of controlled heating and cooling operations applied to a metal part to impart a desired hardness or other metallurgical property, such as for free machining.
Hot Broach: Process of broaching openings in wrenches with special dies while the forging is still hot. (All Martin box end openings over 2" in size are Hot Broached).
Hot Inspection: An in-process examination of forgings, using gauges, templates or other nondestructive methods to ensure quality.
Impression: A cavity, or series of cavities, machined (or re-machined) into a forging die to produce a desired configuration in the workpiece during the forging process.
Impression Die Forging: A forging that is formed to the required shape and size by machined impressions in specially prepared dies that exert three-dimensional control on the workpiece, and which contain a provision for controlling the flow of excess material, or flash, that is generated. Also see Closed Impression Die Forging. (Also used to describe the process of producing such a forging). (This is the process used at Martin Tool & Forge.)
Inclusions: Particles of nonmetallic compounds of metals and impurity elements that are present in ingots and are carried over in wrought products. The shape and distribution of inclusions are changed by plastic deformation and contribute to directionality in metals.
Lap: A surface irregularity in a forging appearing as a fissure or opening, caused by the folding over of hot metal, fins or sharp corners, and, by subsequent rolling or forging (but not welding) of these irregularities into the forged part surface.
Magnetic Particle Testing: A nondestructive method of inspection/testing for determining the existence and extent of possible defects in ferro-magnetic materials. The test metal is magnetized, then iron powder is applied. The powder adheres to lines of flux leakage, revealing surface and near-surface discontinuities.
Mill Certification: The documentation from a steel supplier that the steel delivered meets the chemical (and sometimes the physical) requirements as specified on the order.
Mill Scale: The heavy oxide layer that forms during the heating and forging of steel.
Normalize: A heat treating process whereby the worked steel is returned to it's range of normal "as rolled" properties.
Open Die Forging: A forging produced by working between flat or simple contoured dies with unrestricted metal flow using repetitive strokes and continuous manipulation of the workpiece; sometimes called "hand forging". (Martin capabilities are in Closed Impression Die Forgings)
Parting Line: The inherent line along the surface of a Closed Impression Die Forging where the dies meet, usually at the largest cross section of the part. (Flash is formed at the parting line). Also, the plane that divides the two forging die halves.
Plasters: A reproduction of the die impression obtained by clamping the two dies together and filing the finish impressions with plaster. This is generally part of the initial dimensional inspection and approval process, when beginning the total process of producing new parts from new dies.
Plasticity: (See Plastic Deformation)
Plastic Deformation: The ability of a metal to undergo permanent deformation without rupture.
Plate or Plating: The process of applying external coatings, such as chrome, to the outside surface of the workpiece or hand tool. (Martin utilizes a decorative chrome plating process, in accordance with ANSI standards, which is the application of Chrome over a Nickel base.)
Platter: The entire mass of metal upon which the hammer performs work, including the flash, sprue, tonghold, and as many forgings as are made at one time.
Polish: Term used to describe an extremely fine grit finish to a workpiece. Also used to describe the process of applying the fine finish.
Press Forging: The shaping of metal between dies on a mechanical or hydraulic press. The action is that of kneading the metal, by relatively slow application of force, as compared to the action of a forging hammer. (Martin capabilities are in Drop Forgings)
Pull Broach: A mechanical process for cold broaching openings in wrenches. Also used to describe the machines used to perform this process.
Quench: A controlled heat treating process where the steel workpiece is heated to a prescribed temperature, usually over a prescribed length of time, and then submerged into a fluid to obtain a specific range of metallurgical properties. The fluid may be water, oil, or other as necessary to meet the individual required specifications.
Re-Sink or Re-Sinking: The operation of re-machining the impression cavities of a desired forging into die blocks which have been worn (out of tolerance) from previous use. This is a normal part of the forging process and is typically accounted for in unit part pricing. The amount of useable forgings from a set of dies varies with workpiece shape, applicable material and overall size.
Scrap: The excess, non-usable material from the forging process. Also, non-conforming parts.
Sinking: The original operation of machining the impression cavities of a desired forging into the die blocks.
Stamping: The process of identifying, or branding, our forged products at Martin. The process used for marking Hand Tools is Soft Marking which utilizes either Roll Stamping or Bar Stamping.
When identified prior to the manufacturing process, Commercial Forgings may be Heat Coded at the customer's request.
Stock: The material to be forged, regardless of shape. Also, an individual piece of metal used to produce a single forging.
Straighten: The finishing operation for correcting misalignment, in a forging, or, between different sections of a forging. Straightening may be done by hand, with simple tools, or in a die in forging equipment.
Studs: Small diameter, short sections of steel that are welded to the end of a piece of steel stock that provides a tong hold for the forging process. Usually used on high volume orders utilizing larger diameters of steel stock where this process provides a cost savings.
Temper: A controlled heat treating process, usually employed in conjunction with quenching, to obtain a specific range of metallurgical properties.
Thermal Stress: Stresses in metal resulting from non-uniform distribution of heat.
Tongs: Metal holder used to hold hot (or cold) metal stock (or billets) during the forging process.
Tonghold: That portion of a piece of steel stock where the tongs are applied in order to hold the workpiece during the forging process.
Trim: The removal of the excess metal, or flash, that is produced in the forging process. The operation takes place in tools (tooling, dies, fixtures, etc.) produced to the peripheral shape of the component, the component being pushed through the female impression by the identically-shaped male punch. The operation may be carried out hot, or at room temperature.
Trim Press: A powered press suitable for the trimming of flash from forgings.
Underfill: A portion of a forging that has insufficient metal to give it the true shape of the impression.
Upset Forging: (1) A forging made by upsetting an appropriate length of wire, rod, bar, billet or bloom. (2) Working metal to increase the cross-sectional area of a portion or all of the stock. (3) A forging formed by heading or gathering the material by pressure upon hot or cold metal between dies operated in a horizontal plane. (Upset Forging is the process used by Martin in the manufacture of Offset & T-Handle Socket Wrenches).
Upsetter (Forging Machine): A horizontal forging machine where the workpiece is gripped between two grooved dies and deformed by a punch that exerts force on the end of the stock. (This is the type of machine used by Martin in the manufacture of Offset & T-Handle Socket Wrenches).
Vibratory: A finishing process whereby the part is vibrated, and rotated, while submerged in a bed of specified finishing media. (Martin typically utilizes ceramic media). Also used to describe the machines used to perform this process.
Wheelabrate or Wheelabrator: Term used to describe a process of high velocity abrasive blast cleaning. Also used to describe the machines used to perform this process. This process is typically performed after forging and after any heat treating processes.
3600 McCart Avenue
Fort Worth, TX 76110