Hacksaw Blades Research Articles

Epifluorescence analysis of hacksaw marks on bone: Highlighting unique individual characteristics

Analysis of dismemberment trauma aims at identifying characteristics of false starts and complete sections in order to identify the class of saw. Nevertheless, determination of the individual weapon remains a challenging task. We attempted to determine the unique characteristics of different blades within the same class of saws using epifluorescence macroscopy, a non-invasive technique, in order to establish an individual injury profile. Two hacksaw blades of identical characteristics (size, set and shape of the teeth) were used to create false starts and complete sections on partially defleshed pig bones. These wounds were then analyzed using epifluorescence macroscopy. Bone lesion analysis determined characteristics that were common to both blades, corresponding to size, raker set and ripcut shape. The data collected made it possible to reconstruct the trauma. Furthermore, we highlighted specific characteristics of each blade in both false starts and complete sections. These characteristics mainly related to the shape and profile of the kerf, the consistency of cut and type of fluorescent wall striations. The sum of the information collected in examination of dismemberment wounds can identify, through comparative analysis, the individual weapon responsible for the imprints observed on the bones.

Mechanical Properties and Kinetics of Borided AISI M50 Bearing Steel

The present study reports on mechanical properties and kinetics of borided AISI M50 steel. AISI M50 steel is widely used for critical aircraft engine bearings operating at elevated temperatures with its combination of good hot hardness and excellent rolling contact fatigue strength. AISI M50 is also intermediate high-speed steel which make it suitable for using as woodworking tools and hacksaw blades. Despite its wide range of use, there is almost no published research on the boronizing of AISI M50 steel in the literatures. Boronizing thermochemical treatment was carried out in a solid medium consisting of EKabor-I powders at 850, 950, and 1,050 °C for 2, 4, 6, and 8 h, respectively. The presence of borides FeB and Fe2B on the steel substrate was confirmed via X-ray diffraction analyses and energy-dispersive X-ray spectroscopy. The results of this study indicated that the boride layer has a smooth and compact morphology, and its hardness was found to be in the range of 1,630–2,040 HV. Depending on process time and temperature, the thickness of boride layer ranged from 6 to 216μm. Layer-growth kinetics were analyzed by measuring the extent of penetration of the FeB and Fe2B sublayers as a function of boronizing time and temperature. The fracture toughness of borides ranged from 3.89 to 3.51 MPa m1/2. Moreover, an attempt was made to investigate the possibility of predicting the iso-thickness of boride layer variation and to establish an empirical relationship between process parameters and boride layer thickness.

Ecotechnology for high-speed tool steels

The ecotechnology for high-speed steels produced during the entire metallurgical process is discussed in this paper. Various eco-technologies, including thin-strip casting and comprehensive utilization for the steels, are developed to meet the needs of different types of high-speed tool steel. The as-cast strips were of 2.5–4.0 mm thickness, reduced by hot rolling to 1.8–2.0 mm thickness. The steel sheets were used to make power hacksaw blades. Cutting tests revealed that the performance of these hacksaw blades was satisfactory, compared with that of hacksaw blades made of conventionally produced steel sheets. The recycled utilization of alloying elements in steel scales, oxides, and grinding wastes was carried out. A systematically comprehensive technology of this steel was studied and developed, in which the steel scales were recycled in a closed-loop, the oxides were utilized by self-propagating high temperature reclamation, and the grinding wastes were prepared in a special de-oxidizer and high-speed tool steel matrix composite. These detailed processes are comprehensively introduced in the paper.

Acoustic Emission Analysis of Wear in Hacksaw Blades

The performance and reliability of cutting tools depend on a number of variables such as cutting conditions, tool material, tool geometry, and the properties of the workpiece material. Acoustic emission analysis is a method that may be used to examine the in process progressive wear of cutting tools. This paper presents results of a study of wear processes associated with hand hacksaw blades using acoustic emission analysis. A direct relationship between the mean acoustic signal and the rate of wear has been established for hand hacksaw blades used for metal cutting. This is supplemented by results obtained from SEM and EDAX, which reveal wear in the cutting teeth. Acoustic emission analysis is an attractive technique that can be used to monitor wear processes online and non-obstructively, making it extremely useful for performance and life prediction of hand hacksaw blades. The method may also be applied to other single and multipoint cutting tools.

Thin strip casting of high speed steels

The thin strip casting of high speed steels W3Mo2Cr4VSi and W6Mo5Cr4V2 has been investigated. The as-cast strips are of 2.5–4 mm thickness, reduced by hot rolling to 1.8–2 mm thickness. The steel sheets are used to make power hacksaw blades. The experimental results show that the metallurgical quality of the as-cast strips is now at an acceptable level, and the as-cast carbides in the strips are very fine although the eutectic carbide network still exists. However, most of reveals that the performance of these hacksaw blades is satisfactory, compared with that of hacksaw blades made of conventionally produced steel sheets.

An Analysis of Gravity-Fed Hacksawing for Force and Cutting Rate Prediction

This paper briefly reviews the cutting action and blade performance tests of common hacksawing operations. The acceptance tests for hand hacksaw blade performance in the British Standard and the omission of these tests in the current Australian Standard are also discussed. The analysis presented is particularly relevant to hand hacksaw blade testing conditions. In contrast to previous research on power hacksaw blades, the proposed analysis considers the machine-blade-work-piece as a total system for predicting the forces during the cutting strokes and the cutting rate. The computer-aided model indentifies and incorporates numerous salient machine, blade and workpiece variables. For prediction purposes the model requires both static and dynamic tests of the gravity-fed hacksaw machine as well as limited sawing tests for establishing the tooth force per unit area of cut functions. Good correlation between experimental and predicted forces and cutting rates has been achieved when testing the effects of blade pitch, tooth cutting edge radius, workpiece proportions and added masses on the machine swing-arm assembly. This investigation has highlighted the complexity of this common machining operation and the importance of the machine geometric, kinematic and dynamic features when standardising blade performance tests.

An investigation into factors influencing the wear rate of power hacksaw blades using dimensional analysis

An attempt is made to identify the wear mechanisms involved in power hacksaw blade wear. A method based on dimensional analysis first proposed by Colding has been adapted and is used to relate some of the engineering parameters associated with power hacksaw operations to the wear rate of the blade. The discussion includes some comments on the relevance of the procedures developed to blade wear testing.

A theoretical study of the cutting action of power hacksaw blades

A model of the chip formation process and the forces associated with this formation is proposed and compared with experimental data. The model is used to explain the variation in the cutting performance of power hacksaw blades with changes in the breadth of the workpiece and the pitch of the blade teeth.

Simulation of the cutting action of a single hacksaw blade tooth

The cutting action of tools with very large cutting edge radii has been investigated. These actions have been classified according to the types of chips formed and the variations in the thrust and cutting components of the cutting force obtained. The discussion includes a summary of the implications of the results obtained to the cutting action of power hacksaw blades.

Simulation of the cutting action of a single hacksaw blade tooth

The cutting action of tools with very large cutting edge radii has been investigated. These actions have been classified according to the types of chips formed and the variations in the thrust and cutting components of the cutting force obtained. The discussion includes a summary of the implications of the results obtained to the cutting action of power hacksaw blades.

Factors influencing the savving rate of hard ductile metals during power hacksaw and bandsaw operations

Abstract The chip formation mechanisms produced by both power hacksaw and bandsaw blades are discussed together with some of the main characteristics of sawing machines. Expressions for the cutting rates achieved by various sawing operations are derived and a cutting constant defined. Factors influencing the cutting constant are discussed together with some of the size effects observed. While the mechanisms described are applicable to most hard ductile metals, emphasis is given to steel.

New steel for band saw and hacksaw blades

New steel for band saw and hacksaw blades

A Sharpening Machine for a New Type of Microtome Knife

ABSTRACT A description is given of the manufacture of a new type of microtome knife made from selected portions of discarded low tungsten steel power hacksaw blades. A machine for sharpening this type of knife is described. Its main feature is a lapping plate of 14 in. plate glass which can be adjusted for height to give cutting angles ranging from 24 to 32°, these angles being accurately reproducible on resharpening. Results of tests with a series of knives covering this range of cutting angles is given.

Performance of Cutting Fluids When Sawing Various Metals

Abstract This paper presents the results of a series of tests conducted on a Peerless high-speed, 9-inch-capacity hacksaw. Two types of tests were runs: The first to determine the influence of four typical cutting fluids on the wear of the teeth of tungsten-steel hacksaw blades, the second to determine the influence of eleven cutting fluids on high-speed-steel blades when sawing each of eight different metals. The time required to saw through a 1½-inch-square section of each metal was obtained and used to indicate the performance of the cutting fluid. In these tests high-speed-steel hacksaw blades were used, inasmuch as they retained the initial degree of sharpness without visible change throughout the test. The comparative tests were run at constant speed and constant feeding pressures. It is shown that a mineral-lard oil causes the tungsten-steel blades to wear fastest. Plain mineral oil produces the next fastest degree of wear, followed in order by an emulsion and a sulphurized mineral oil. The sulphurized mineral oil permitted the least degree of dulling on the saw blades and, at the same time, kept the sawing time to a time below that for any of the other cutting fluids. Cutting fluids produced a rather wide variation in cutting time when cutting steels, but gave more uniform values when cutting aluminum, malleable cast iron, cast iron, and brass.