Shear Blade Research Articles

SAE 8655

Abstract SAE 8655 is a triple-alloy steel that is normally hardened by quenching in oil; however, it may water quenched if sufficient precautions are taken with parts having drastic dimensional changes or sharp corners. Its good hardenability and resultant hardness and strength make it suitable for many tools and machine parts such as wrenches, shear blades, shafts, springs and gears. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-424. Producer or source: Alloy steel mills and foundries.

SILICO ALLOY

Abstract SILICO ALLOY is a silicon-manganese shock-resisting tool steel; it has high toughness at relatively high operating hardnesses. It is primarily an oil-hardening steel because of its molybdenum content (0.45%); however, it may be water hardened. It is a low-cost, high-quality steel that combines high toughness with the advantages of oil-hardening non-deforming steels. Its relatively high hardenability coupled with high toughness makes it extremely useful for larges shear blades in severe service. Other applications include pneumatic tools, punches, hand chisels, rivet sets and pipe cutters. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: TS-473. Producer or source: Columbia Tool Steel Company.

Effects of land clearing and tillage methods on soil properties and maize root growth

The effect of six methods of land clearing and postclearing tillage systems on soil hydrologic properties, root development and nutrient concentration in ear leaf of maize ( Zea mays L.) were investigated on an Alfisol in south-western Nigeria. The land clearing methods were manual, tree pusher and root rake, shear blade, and traditional. The tillage methods in manual and tree pusher treatments comprised no-till and conventional tillage systems. The tilled plots were terraced to control erosion. At a depth of 0–10 cm, tree pusher/conventional tillage had significantly lower moisture content than other treatments. At a depth of 20–40 cm soil moisture content was in the order: traditional clearing and management > tree pusher/no-tillage > shear blade/no-tillage > manual clearing/no-tillage > tree pusher/conventional tillage > manual clearing/conventional tillage. The unsaturated hydraulic conductivity was lower in tilled than untilled treatments at 10–20 cm depth, but at 20–40 cm depth there was no significant difference among treatments. Root weight densities (mg/cm 3) sampled at 10 and 12 weeks after planting were: 0.37 and 0.41 for tree pusher/no-tillage; 0.38 and 0.46 for tree pusher/conventional tillage; 0.55 and 0.61 for manual clearing/conventional tillage; 0.56 and 0.67 for manual clearing/no-tillage; 0.58 and 0.69 for shear blade/no-tillage; and 0.85 and 1.03 for traditional clearing and management. Root length densities sampled at grain filling stage were the maximum under traditional clearing and management compared with the other treatments. Macro-nutrients (nitrogen, phosphorus, potassium, calcium and magnesium) concentration in ear leaf of maize were greatest for manual clearing/no-tillage, followed by traditional clearing and management, and were smallest in tree pusher/no-tillage treatment.

Effects of Land Clearing and Subsequent Management on Soil Physical Properties

AbstractLarge scale, mechanized land clearing is common in the humid tropics even though little attention has been given to defining and solving soil problems that may be created. The purpose of this study was to evaluate various combinations of land clearing method, burning of vegetation, post clearing tillage, and soil management on soil physical properties of a forested Ultisol in the Amazon basin. Land clearing methods used were (i) slash, (ii) bulldozer clearing with a straight blade, and (iii) bulldozer clearing with a shear blade. Specific effects associated with clearing were mechanization, bulldozer blade type, burning, disking, and chiseling. Post clearing soil management systems isolated effects of bedding, liming, and fertilization. Soil physical properties were measured before clearing and 14, 29, and 98 weeks after clearing. Compaction increased bulk density (ρb) of the 0‐ to 15‐cm depth for all clearing methods, but ρb of the 15‐ to 25‐ depth increased by 0.1 Mg m−3 only for the bulldozer cleared treatments. Soil texture of the 0‐ to 15‐cm depth was not altered by land clearing. Gravimetric water content at soil matric potentials < −2 kPa was greatest for the straight blade cleared soil. The infiltration rate 14 weeks after clearing decreased 37, 96, and 90% for soil cleared by slash, straight blade, and shear blade, respectively, as compared to initial conditions. Chisel plowing and disking the newly cleared land increased the infiltration rate compared with straight blade without chiseling. Detrimental changes in soil physical properties caused by clearing were minimized when post clearing management practices of bedding, fertilization, and liming were adopted.

EFFECT OF LAND-CLEARING METHODS AND POSTCLEARING MANAGEMENT ON AGGREGATE STABILITY AND ORGANIC CARBON CONTENT OF A SOIL IN THE HUMID TROPICS

The objective of this study was to evaluate the effects of land-clearing methods and subsequent soil management on aggregate stability and soil organic carbon (OC) content in the 0− to 15-cm depth. The 2-yr-long study, beginning in July 1980, was conducted on Yurimaguas soil (fine-loamy, siliceous, isohyperthermic Typic Paleudult) in the Amazon jungle of Peru. The site was initially covered with a 20-yr-old secondary evergreen forest. Land-clearing methods were: (1) slash-and-burn, with logs removed by hand, but stumps remaining in place; (2) mechanical clearing with a bulldozer with a straight blade; and (3) mechanical clearing with a bulldozer with a shear blade. Soil samples were taken before clearing and at 3, 8, and 23 mo after clearing. After the second soil sampling, various land-preparation techniques were superimposed upon the three clearing methods to give a total of six land clearing-soil management treatments. Each treatment was split in three subtreatments: (1) flat-planted with no fertilizer or lime, (2) flat-planted with recommended rates of fertilizer and lime, and (3) bedding with fertilizers and lime. The third and fourth sets of soil samples (8 and 23 mo after clearing) were taken prior to harvesting the first and fifth consecutive crops, respectively. Straight-blade clearing reduced mean weight diameter (MWD) and OC by 39 and 21%, respectively. The least change in these two soil properties occurred for slash-and-burn clearing, with an 11 % reduction in MWD and no change in OC. No significant changes in the percentages of five water-stable aggregate size classes occurred between 8 and 23 mo after clearing. Soil-management practices, such as bedding and lime application, tended to maintain aggregate stability and OC levels of newly cleared land during the first 2 yr of continuous cropping.

AL TECH CHEROKEE

Abstract AL TECH CHEROKEE is a high-carbon, high-chromium die steel containing nominally 3.25% cobalt. The cobalt provides effective resistance to galling and pickup as well as improved hot hardness. The cobalt enables this steel to perform exceptionally well on both extended cold-work and moderate hot-work applications. Another feature of this versatile die steel is its outstanding secondary hardness associated with remarkable tempering resistance up to 900 F. Typical applications comprise blanking dies, swaging dies, hot and cold-piercing punches, forming rolls, shear blades and coining dies. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-465. Producer or source: AL Tech Specialty Steel Corporation.

Laboratory studies of the cutting of grass stems

Studies were undertaken of the principle of employing static elements to support stems during cutting, using a relatively large clearance (about 5 mm) with a moving blade or blades. The objective of the work was to examine whether cutting speeds could be significantly reduced below the 80 to 90 m/s used in practice. Equipment was constructed which employed a piezoelectric force transducer to measure the specific force and energy for a single stem during a cutting cycle at speeds up to 45 m/s; high speed cine photography was used to study stem kinetics. Work was done on the effect of cutting speed, blade arrangement, clearance between static and moving elements, blade rake angle and blade sharpness. In addition, studies were made of restraint at the tops of stems, cutting of groups of stems and stem inclination. The results showed a critical cutting speed of 15 to 30 m/s, below which cutting became progressively more inefficient in terms of specific cutting energy. Relatively low energies were recorded at 5 to 10 m/s when stems remained uncut. The double shear blade arrangement was the most effective. The clearance between blades had no significant effect in the range 2 to 5 mm. Sharp blades required about 1 3 of the specific energy and peak force at speeds below the blunt blades. Increasing rake angle reduced specific energy and peak force at speeds below the critical value. For stems rigidly clamped at the top, the specific cutting energy was markedly reduced. A group of stems required significantly greater specific energy and peak force than a single stem. Highly inclined stems (at 70° to the vertical) required critical speeds greater than 40 m/s.

FIREDIE 13

Abstract FIREDIE 13 is the standard 5% chromium hot-work tool steel with increased vanadium for improved wear resistance and toughness. In addition, this steel possesses excellent hot-hardness properties. Its many applications include die-casting tools (for Al, Mg and Zn), extrusion tools (for Al and Mg), hot-heading dies, forging dies, hot punches and heavy shear blades. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-462. Producer or source: Columbia Tool Steel Company.

BUSTER ALLOY 60

Abstract BUSTER ALLOY 60 is a widely accepted tungsten shock-resisting tool steel. Its performance is unequalled in most shock and impact tools used under very demanding conditions. It is deep hardening and combines this quality with excellent wear resistance and good toughness. Buster Alloy 60 will withstand repeated heating to 700-800 F, when used in lower temperature hot-work applications. Among its many uses are shear blades, hand chisels, pneumatic tools, coining dies, hot-heading dies, forging dies and machine parts. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-455. Producer or source: Columbia Tool Steel Company.

UNS T20812

Abstract UNS No. T20812 is a low-carbon chromium-molybdenum-tungsten hot-work steel for general purposers. It is used for dies and tools that require high toughness. It has high hardenability and offers high resistance to softening in service at elevated temperatures. It also offers good resistance to heat checking and may be water cooled in service. It is suitable for hot-work applications involving severe conditions of shock and sudden temperature changes. Its many applications include hot shear blades, forging dies, extrusion dies, punches and other types of hot-work tools. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-453. Producer or source: Tool steel mills.

COLUMBIA S6

Abstract COLUMBIA S6 is a silicon-manganese shock-resisting tool steel with fairly high hardenability. It offers superior toughness and wear resistance when compared to conventional shock-resisting steels heat treated to Rockwell C 54 to 56. For optimum strength and toughness, parts should be tempered within the range 400 to 600 F. Among its many applications are shear blades, punches, hand chisels and pneumatic tools. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-445. Producer or source: Columbia Tool Steel Company.

LESCO S-7

Abstract LESCO S-7 is an air or oil-hardening die steel with a unique combination of toughness and wear-resistance properties that makes it an ideal choice for many tooling applications. The outstanding properties of Lesco S-7 are provided by an intermediate carbon level balanced with moderate amounts of chromium and molybdenum. It is used for both cold and hot tooling applications. Its many uses include shear blades, swaging dies, chisels and dies for molding plastics below 1000 F (538 C). This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, joining, and surface treatment. Filing Code: TS-437. Producer or source: Latrobe Steel Company.

AIRKOOL

Abstract AIRKOOL is a high-hardenability (deep-hardening) tool and die steel that is intermediate in abrasion resistance between the oil-hardening and high-carbon high-chromium tool steels. It possesses superior toughness to both of these types; furthermore, AIRKOOL can be machined readily and has excellent non-deforming characteristics. It is well suited for applications requiring toughness and fairly high resistance to abrasion. Typical applications for AIRKOOL include blanking dies, forming dies, punches and shear blades. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-435. Producer or source: Crucible Specialty Metals Division, Colt Industries.

Energy and Force Requirements for Shearing Moduled Almond Prunings

ABSTRACT CROSS grain shear tests were conducted on small groupings of almond tree prunings. Differing specimen size distributions were tested for their relation to shear force and energy. Tests were conducted with various shear chamber widths and blade geometries. Compression and bending tests were also conducted on individual samples. The results are analyzed and extrapolated to determine force and power requirements for shearing modules of almond prunings made with conventional or modified heavy duty cotton module builders.

Finite element dynamic analysis of blade shear center effects on practical bladed discs

Dynamic characteristics of rotating and non-rotating practical bladed discs have been investigated by taking blade shear center effects into account. Both, thin or thick beam and plate theories, and the finite element method have been used in the analysis. The disc has been modelled by conforming sector disc elements, and the blades by classical thin beam and 18 degrees of freedom thick beam models. Shear center effects have been shown by comparing calculated values for different models and available calculated and experimental values obtained by others. It has been found that when these effects in the blade are high the bladed disc vibration characteristics can also be considerably changed.

JESSOP SUPERSHOCK 7

Abstract JESSOP SUPERSHOCK 7 is an air-hardening shock steel having excellent toughness combined with good resistance to softening at temperatures up to 1000 F. It is suitable for both hot and cold-work tooling applications that involve shock. Among its typical applications are dies, shear blades, chisels and punches. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-422. Producer or source: Jessop Steel Company.

Diurnal fluctuations in hydro‐thermal regime of a tropical alfisol as influenced by methods of land development and tillage systems

AbstractThe nature of diurnal fluctuations in soil moisture profile, moisture potential profile, and soil temperature regime was investigated for soils under five different methods of land clearing and post clearing tillage systems on an Alfisol in south‐west Nigeria. The treatments consisted of manual clearing with terraced conventional tillage, manual clearing with no tillage/mulch, shear blade – no tillage/mulch, tree pusher – terraced conventional tillage, and traditional clearing and management. Soils under no‐tillage mulch and traditional managements had more favourable hydrothermal regime than mechanically cleared plowed treatments. Compared with traditional farming, the maximum soil temperature at 5 cm depth was more by 2°C for tree pusher conventional tillage, 1.5°C for manual clearing conventional tillage and 0.7°C for manual clearing no‐tillage and shear blade no‐tillage, respectively. Water loss in the 1 to 4 cm depth increment in 24 hours was 2.9 mm for the manual clearing conventional tillage, 3.1 mm for the tree pusher conventional tillage, 2.0 mm for the manual clearing no tillage and 2.2 mm for the traditional clearing and management.

AL TECH NAVAHO

Abstract AL TECH NAVAHO is an air-hardening punch and die steel with lower carbon than most cold-work steels; this provides an optimum combination of wear resistance and toughness for difficult cold-work applications. It also is used for abrasive hot-work requirements. This steel offers relatively favorable size stability and exceptional secondary hardness characteristics. NAVAHO has a broad application range from shear blades and punches to molds for plastics ad hot-work tooling. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-421. Producer or source: AL Tech Specialty Steel Corporation.

AISI TYPE L2

Abstract AISI Type 1.2 is a chromium-vanadium tool steel of modest hardenability and variable carbon content (nominally 0.50-1.10% carbon). At its lower carbon levels, it is used for tools requiring toughness and resistance to shock and vibration. At its higher carbon levels, it is recommended for resistance to abrasion, fatigue and wear. It is used for both hot-work and cold-work applications. Among its many uses are automotive gears, forgings, gun barrels, shafts, wrenches, chisels, punches, lathe spindles, axes, shear blades, dies, files, reamers and drills. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-416. Producer or source: Tool steel mills.

GUTERL S-7

Abstract GUTERL S-7 is a chromium-molybdenum, general-purpose, air-hardening tool steel recommended for uses where shock resistance, good hot-work properties, good wear resistance, excellent toughness and easy machining are important. These properties make it suitable for many hot-work and cold-work applications. Among its many uses are blanking dies, shear blades, punches and chisels. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and surface treatment. Filing Code: TS-414. Producer or source: Guterl Special Steel Corporation.