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Backing Board (Backing Plate)
A second bottom board on which molds are opened.
Bainite
In steel, an acicular aggregate of ferrite and carbide, resulting from an isothermal transformation of austenite at a temperature below the pearlitic range and above Ms.
Bake
Heat in an oven to a low controlled temperature to remove gases or to harden a binder.
Baked Core
A core which has been heated through sufficient time and temperature to produce the desired physical properties attainable from its oxidizing or thermal-setting binders.
Baked Strength
Compressive, shear, tensile or transverse strength of a mold sand mixture when baked at a temperature above 231°F (111°C) and then cooled to room temperature.
Ball Burnishing
A method of obtaining a high luster on small parts by rotating them in a wooden-lined barrel with water, burnishing soap, and stainless steel shot.
Band, Inside
A loose steel frame placed inside a removable flask to reinforce the sand at the parting line after the flask has been removed.
Bark
The decarburized layer just beneath the scale resulting from heating steel in an oxidizing atmosphere.
Bars (Cleats)
Ribs of metal or wood placed across the flask to help support the sand in the cope.
Base Plate
A plate to which the pattern assemblies are attached and to which a flask is subsequently attached to form the mold container.
Batch
Amount or quantity of core or mold sand or other material prepared at one time.
Batch Oven
Oven use to bake a number of cores at one time.
Bath
Molten metal on the hearth of a furnace, in a crucible, or in a ladle.
Batten
A wooden bar or strip fastened to bottom or follow board for rigidity or to prevent distortion during ramming of the mold.
Bead
1)Half-round cavity in a mold, or half-round projection or molding on a casting, 2) a single deposit of weld metal produced by fusion.
Beam and Sling
Tackle used in conjunction with a crane for turning over the cope or drag of a mold prior to assembly.
Bedding
Sinking a pattern down into the sand to the desired position and ramming the sand around it.
Bedding a Core
Resting an irregularly shaped core on a bed of sand for drying.
Bed-In
Method whereby drag may be rammed in the pit or flask without necessity of rolling over. Process used in production of heavy castings.
Bench-Blower
A small core-blowing machine, utilizing a removable sand magazine and blow heat.
Bench Rammer
A short rammer used by bench molders.
Bending Strength
Upper limit of normal stress of a beam at which fracture or excessive plastic deformation occurs.
Bentonite
A colloidal clay derived from volcanic ash and employed as a binder in connection with synthetic sands, or added to ordinary natural (clay-bonded) sands where extra strength is required.
BHN
Brinell Hardness Number
Bimetal
Casting, usually centrifugal, made of two different metals, fused together.
Black Lead
A natural form of graphite used for sleeking green sand molds, or applied in a water suspension to skin dried molds.
Blackening Scab
A form of casting defect related to an improper coating rather than to the sand.
Blacking Carbon
Carbonaceous materials such as plumbago, graphite or powdered coke usually mixed with a binder and frequently carried in suspension in water or other liquid; used as thin facing applied to surfaces of molds or cores to improved casting finish.
Blacking Hole
Irregular-shaped surface cavities in a casting containing carbonaceous matter. Caused by spilling off of the blacking from the mold surface.
Blacking Scab
A casting defect formed by blacking flaking off due to sand expansion and being retained in or on the surface of the metal.
Blasting (Blast Cleaning)
A process for cleaning or finishing metal objects by use of an air blast or centrifugal wheel that throws abrasive particles against the surface of the work pieces. Small, irregular particles of steel or iron are used as the abrasive in grit blasting, and steel or iron balls in shot blasting.
Bleeder
A defect wherein a casting lacks completeness due to molten metal draining or leaking out of some part of the mold cavity after pouring has stopped.
Blended Molding Sands
Naturally bonded molding sands which have been mixed or modified by the supplier to produce desirable properties.
Blister
A shallow blow with a thin film of the metal over it appearing on the surface of a casting.
Blocking
Adding ferrosilicon or other deoxidizing agent to a refined heat to stop all oxidizing reactions.
Blow Holes
1) Holes in the head plate or blow plate of a core-blowing machine through which sand is blown from the reservoir into the core box. 2) Irregular shaped cavities with smooth walls produced in a casting when gas is entrapped during mold filling. The gas sources may be air, binder decomposition products or gases dissolved in the molten steel.
Blow Plate
The plate containing the core sand entrance holes or blow holes used in open-face core boxes.
Blower, Core or Mold
A device using air pressure to fill a core box or flask with sand.
Blowing-Off a Mold
Cleaning a mold cavity with a stream of compressed air.
Blowpipe
A small pipe or tube through which the breath is blown in removing loose sand from small mold cavities.
Blows
See Blowholes
Bluing
Formation of a thin film of oxide on polished steel to improve its appearance and protect its surface.
Bob
A riser or feeder, usually blind, to provide molten metal to the casting during solidification, thereby preventing shrinkage cavities.
Body Core
The main core.
Boil
Agitation of a bath of metal caused by the liberation of a gas beneath its surface. May be deliberately induced by the addition of oxidizing material to a bath containing excess carbon. In the later case it is called a carbon boil and CO or CO2 are liberated.
Bond
1) Bonding substance or bonding agents - any material other than water, which, when added to foundry sands, imparts bond strength, 2) the overlapping of brick so as to give both longitudinal and transverse strength.
Bond Strength
Property of a foundry sand to offer resistance to deformation.
Bonding Clay (Bonderise)
Any clay suitable for use as a bonding material.
Boring
A machining method using single point tools on internal surfaces of revolution.
Boss (Pad)
A projection of circular cross-section on a casting. Usually intended for drilling and tapping for attaching parts.
Bottom Pour Ladle
See Ladle, Bottom Pour
Bottom Running or Pouring
Filling of the mold cavity from the bottom by means of gates from the runner.
Bracket
Strengthening strip, rib, or projection on a casting; usually used to prevent hot tearing.
Also see cracking Strip
Breaker Ring
An intentionally weak ring within mass of a ring shell mold to be broken by force of casting shrinkage. Prevents hot tear stress.
Breakoff Notch
A thinner section of a gate or riser to facilitate and ensure clean breaking-off during the cleaning process of casting.
Bright Annealing
A process carried out usually in a controlled furnace atmosphere, so surface does not oxidize, remaining bright.
Brinell Hardness
The value of hardness of a metal on an arbitrary scale representing kg/mm2, determined by measuring the diameter of the impression made by a ball of given diameter applied under a known load. Values are expressed in Brinell Hardness Numbers, BHN
Brittle Fracture
Fracture with little or no plastic deformation.
Brettleness
A tendency to fracture without appreciable deformation.
Broaching
Smoothing machined holes or outside surfaces of castings by drawing pushing on or more broaches (special cutting tools) through the roughed out hole.
Buckle
1) Bulging of a large flat face of a casting; in investment casting, caused by dip coat peeling from the pattern, 2) an indentation in a casting, resulting from expansion of the sand, may be termed the start of an expansion defect.
Builtup Plate
A pattern plate of suitable material, with the cope pattern mounted on or attached to one side; the drag pattern may be attached to the other side or to a separate mounting.
See Matchplate
Bulk Density
The ratio of the weight of a material to its over-all volume (including any inherent porosity).
Bull Ladle
See Ladle, Bull
Bumper
A machine for ramming sand in a flask by repeated jarring or jolting.
Burn
1) Process of cutting metal by a stream of fuel and oxygen, 2) to permanently damage a metal or alloy by heating to cause either incipient melting or intergranular oxidation.
Burned Sand
Sand in which the binder or bond has been removed or impaired by contact with molten metal.
Burned-On-Sand
A misnomer usually indicating metal penetration into sand resulting in a mixture of sand and metal adhering to the surface of a casting.
Burning In
See Penetration, Metal
Burnishing
Developing a smooth finish on a metal by tumbling or rubbing with a polished hand tool.
Burnthrough
In shell molding, resin burned out too soon.
Butt Off
Operation performed at times to supplement ramming by jolting, either hand or air rammer.