Scissors and Shears Terms
Balance: The final adjustment steps of scissors and shears are referred to as balancing or finishing.
Bearing: Any material between the screw and the blade it pivots on is a bearing. This may be a nylon washer or a tiny ball bearing.
Bow: (see SET)
Bumper: Between the handles (at the point they touch) of fine barber and beauty shears, there is often a small rubber or plastic shock absorber, called a silencer or bumper. This serves as a stop for the shears and keeps them quiet as the handles come together.
Carbide: Carbide is fine particles of metal combined with carbon. It is harder and more brittle than hardened steel. Because of its hardness, it is used for masonry drill bits and metal cutting saws.
Carbon Steel: Carbon steel is iron (fe) with about .5% - .8% carbon added for hardening. A carbon content that is too high causes extreme brittleness.
Cast: Casting is metal poured into molds while heated to a liquid state. This is not commonly used, except for cast iron shears.
Ceramic: Ceramic is a porcelain like material, (usually with a high alumina content), pressed from a powder and fused at high temperature. Ceramics are very hard and have a long wear life, but are also brittle and subject to breakage and chipping. Ceramic shears are best returned to the importer for sharpening.
Clamshell: (see CONVEX)
Convex Blade: The outside of a convex blade flows (rounded) into the cutting edge without an obvious bevel. This adds strength to the blade and cutting edge.
Corrugation: Corrugations are small teeth on the scissors cutting edge (one or both blades) that provide holding power to keep the material (hair, fabric..etc) from sliding. These are found mostly on pet grooming or low priced barber and beauty shears.
Crescent: (see RIDE)
Cut Length: The length of cut is measured from the pivot to the tip on scissors and shears.
Forged: Forged shears are stamped to shape while the metal is red hot (soft). This produces high carbon shears that are good to high quality. Most large tailor and industrial shears are made this way.
Free Fall: Free fall is the measurement of how far the scissors close while holding one blade tip pointed up and letting the other handle drop. This may be considered the point where the blades contact each other.
Half-Moon: (see RIDE)
Hamaguri-Ba: (see CONVEX)
Hardening: Martinsitic (hardenable) steels are heated to 1550 degrees F for carbon steel and 1950 - 1975 degrees F for Stainless. They are then quenched rapidly. Carbon steel is usually heat treated in salt pots, by immersing blades to just past the ride. This leaves the handles soft, so that they can be bent to size the tips. Stainless steel is often done the same way. When stainless is hardened in a vacuum oven, the entire blade and handle are hardened. It is hard to bend these handles without breaking them. After quenching, blades are cooled to about -100 degrees F. This convert retained austinite (soft) particles to hard martinsite. The steel is now very hard, but extremely brittle and must be drawn in an oven at 375 - 400 degrees F for about 1 hour to make it flexible (ductile).
Hardness: Metal hardness is measured using the Rockwell C scale. Good quality shears 54 - 60 (sometimes 61-62), Files 60 - 62, Drill bits 52 - 55.
Haura-Ichban: (see LINED INSIDE EDGE)
Hineri: (see TWIST)
Hinzoko: (see HOLLOW GRIND)
Hollow Grind: The inside of a hollow ground scissors blade, from the cutting edge to the back of the blade, is concave or hollowed-out. This hollowed-out area produces a lined inside edge which gives a smoother feeling cut (less metal to rub). Most finer, high quality, barber and beauty shears are ground this way.
Ice: This is a metal hardening process. Stainless steel is heated to almost 2000 degrees F and then cooled to about -100 degrees F. All quality shears are ice tempered, even if not marked.
Induction Hardening: Some lower quality shears are hardened by induction heat treating on the cutting edge. This heat treating is only about 1/8" deep, because of this as the shears are sharpened softer metal is exposed. These shears will not hold a sharp edge very long after the hardened surface has been removed.
Knife Edge Shears: A knife edge shears has two angles, one blade at about 20°, this blade is called the "anvil" or flat blade. The other blade, the knife edge is about 50°. A knife edge shears is used to cut through thick materials like upholstery fabric. It is most common to find a knife edge on metal bent trimmers 8" and larger.
Left Hand Shears: True left hand shears have the blades reversed. The thumb blade is on the right hand side of the finger blade. Some shears claim to be left hand, but are really true right hand shears with handles made to fit the left hand.
Left Handled Shears: The handle is designed for left hand use but the blades are not reversed. This is a right hand shears with a left hand handle.
Length: Scissors and shears are measured overall from tip to the end of the handle (including any tang or finger rest).
Lined Inside Edge: The lined inside edge is located on the inside of the blade at the cutting edge. This area is usually very smooth and is found on hollow ground shears (see HOLLOW GRIND).
OOKAMI GOLD®: OOKAMI GOLD® is the perfection of a scissors sharpening method.
Overlap: The blades most cross one another (overlap) all the way to the tip to perform the cutting action (see SIZING).
Pivot: A pivot can be any fastening device that holds the scissors blades together.
Ride: The ride is the area just behind the pivot and where the two blades come together (see SET).
Scissors: Scissors are usually smaller than shears and only have room for one finger and the thumb.
Set: The set of the scissors is the amount of gap between the blades. With the blades closed, only the tips and the ride actually touch. The set provides the spring pressure that causes the blades to stay touching during the cutting action. Too much set and the blades cut into one another or are very tight. Too little, and the material being cut folds between the blades.
Shears: Shears are usually larger than scissors and have room for more than one finger and the thumb.
Silencer: (see BUMPER)
Sintered Metal: Made in powdered form, scissors are pressed to shape, then hot isostatic pressed to form a solid piece of metal.
Sizing: Sizing is setting the overlap of the blades, especially the tips.
Sori: (see SET)
Stainless Steel: Stainless steel is made from steel with 11% to 18% chromium added for high quality and hardness. Stainless steel shears have 16% to 18% chromium. Also, the addition of manganese and molybdenum add hardness and toughness. Cobalt may be added for improved feel and toughness.
Stamped: The shears blades are stamped from rolled steel using a formed die. These are the lowest cost shears to produce and are often very durable, but may not be as smooth feeling. Most plastic handle fabric shears are made this way.
Steel: Iron with carbon and other elements added.
Tang: An extension beyond the end of a scissors handle that provides a finger rest would be considered a tang. Some tangs are removable.
Titanium: Titanium is a gold colored microscopic coating added to shears to improve wear life.
Twist: In some scissors the set of the blades is provided by twisting the blades toward one another. This is common in many European scissors (see SET).