# Bill Toulas

Passionate engineer and new technologies advocate, writing about the ways they shape our world and amplify our very existence. Believes that engineering is the art of changing this world forever, everyday, little by little, and sometimes all at once.

## Tap Drill Chart â€“ The Ultimate inch and metric table (mm and inches)

Do you need to see the Drill and Tab chart right now? Jump to Tab Drill Chart. Taps are cutting tools used by machinists to cut or form screw threads. The first recorded use of taps in metalworking is placed sometime in the 18th century, while the British engineer and industrialist Joseph Clement popularised the …

## Magnetic Bearings – The mechanical engineer’s guide

As the name suggests magnetic bearings use magnetic levitation to support the rotating shafts, without directly contacting them, thus there is no friction. As we all know, less friction means less energy wasted and greater overall efficiency. The very first patent relating to the magnetic suspension of rotating elements was submitted in the 1940s. However, …

## The Melting Point of Steel Alloys

In simple terms, the melting point of steel for example, is the temperature when it starts to change from a solid state to a liquid. At this specific melting point temperature both phases of the substance exist in equilibrium. Therefore, further heating needs to be passed through the substance to complete the transition from solid …

## Taylor Functions – explanation and software tools

The Taylor Functions are series of sum terms that concern the values of the derivatives of a given function at a given point, so they are a part of Calculus. They are a clever practical way to expand and simplify complicated and transcendental functions into computable polynomials. The number of the sum terms that are …

## Dynamometer – types, working principle and power measurement basics

A dynamometer is a power measurement instrument used to determination the work being done by a machine over time. Work is the force vector that acts in such a way and direction that it results in the displacement of a mass. So, the action of lifting a bucket of water in a time period of …

## Surface Roughness Chart & Useful Information

The surface roughness chart is a concept that expresses the amount and extent of deviation of a surface from being perfectly flat. As it is practically impossible to manufacture a completely flat surface on the microscopic level, every surface has a certain value of roughness that can be measured with the use of a profilometer. …

## Structural Concepts – Static and dynamic load basics

Defining and understanding the basic structural concepts of engineering and how they are expressed in physics and mathematics is a key aspect for students. This enables them to enter the realms of structure design and development on the right foot. The purpose of this quick guide is to provide a generic yet helpful description of …

## AISI 304 Stainless Steel: Specification and Datasheet

The SAE/ANSI 304 (AISI 304) is the most commonly available and used type of stainless steel. It is also referred to as 18/8 stainless steel, A2 stainless steel (as per the ISO 3506), or 304S15 (as per the British Standard). This is an austenitic chromium-nickel alloy which practically means that it has a very high …

## AISI 316 Stainless Steel: Specification and Datasheet

The SAE / ANSI / AISI 316 is the second most commonly available/widely used type of stainless steel after the SAE/ANSI/AISI 304. Considered the generic workhorse, the SS 304 can serve in most situations with great success. However, while both are typically used in industry, the SS AISI 316 is used in even harsher environments …

## Material Database – Top 9 Engineering Materials Resources on the Web

A material database is a great way to store material data according to their type, physical characteristics, mechanical properties, and standard classifications. This makes material databases a great tool for any engineer, and with the rise of the internet, these have become accessible by everyone from everywhere –Â  another powerful tool in the engineer’s arsenalÂ that …

## IP Ratings – A Guide to IEC 60529 / EN 60529 Ingress Protection Ratings

Any mechanical design engineer who designs enclosures MUST have a firm grasp of IP ratings. IP stands for “Ingress Protection” and is a standard protection marking for casings and enclosures of electrical and electronic products. It helps to classify them according to their degree of protection against solids and liquids. The standard IP ratings were …

## How does a Harmonic Drive work? Why are they used?

The harmonic drive is a type of gear arrangement often referred to as a strain wave gear because of the way it works. It is a kind of reduction gear mechanism consisting of a minimum of three main components. These components interact in a way that allows for very high precision reduction ratios that would …

## How does a Centrifugal Clutch work? What are the pros and cons?

The centrifugal clutch is a clutch that bases its operation on the principle of centrifugal force generation. It is generally considered one of the smoothest types of clutches as it engages the load to the engine gradually, allowing the engine to reach its optimal torque range before it has to carry any loads. This is …

## 6061 Aluminum Properties

It is theÂ 6061 aluminum properties that make it one of the most widely used aluminum alloys, being applied in various fields since 1935. A member of the “6000” alloy series, it typically consists of 97.1% aluminium, 1% magnesium, 0.7% iron, 0.5% silicon, 0.3% copper, 0.2% chromium, 0.1% zinc, 0.05% manganese, and 0.05% titanium. 6061 Aluminum …

## What is a Profilometer and why is it used?

A profilometer is a highly specialised meteorological measurement device that is used for the determination of the roughness of a surface. As a measurement instrument, the profilometer is very precise as it is expected to have the capacity to identify and quantify very small-scale surface features. The roughness of a surface is categorised in grades …

## Compression Springs – Types, calculations and more

Compression springs are mechanical devices that are specifically designed to be induced to axial compression loads. They can usually also be extended as well as rotated up to a point. In general, compression springs can store mechanical energy when a compression load is applied to them. They will return back to their original shape and …

## Types of Gears – a guide to 11 important types you must know

Many people might not be aware but there is a whole range of different types of gears on the market today.Â  Every mechanical engineer must have a basic understanding of the main types of gears that exist. In layman’s terms gears are rotating mechanical elements that are generally used for the purpose of transferring torque …

## 6061-T6 Aluminium – The Ultimate Guide

Aluminium 6061-T6 is a subcategory of the 6061 aluminium alloy, one of the most widely used aluminium alloy categories in the world. The alloy is appreciated because of its versatile performance and all-around mechanical properties . The “T6” part of the 6061-T6 name indicates the type of the tempering treatment process that this aluminium alloy …

## Pipe Size Chart & Common Pipe Schedule Chart

Pipes are extensively used in mechanical engineering, from the Oil & Gas industry and their offshore rigs to the more simplistic home tap water networks, these hollow sections made of metal or plastics are essential for a very wide spectrum of applications. Before we head into the details of their standardization, it is important to …

## Basic Thermal Calculations

Thermal engineering is one of the most fundamental areas of mechanical and chemical engineering, with the study of heat transfer being one of the most significant disciplines. Heat is energy, so heat transfer is practically energy transfer that takes place in small scale but affects large systems such as renewable energy harvesting units, industrial cooling …

## Maraging Steel: Unique Properties and Uses

While there are many materials which are tough and long-lasting and others which are malleable it is difficult to find materials which have all of these characteristics. This is why maraging steel is so important in the world of mechanical engineering and why it plays a major role in our everyday lives. What is Maraging …

## Basic stress analysis calculations

Mechanical engineers need to be able to calculate things! One of the most important things a mechanical engineer must know are basic stress analysis calculations. This guide covers all the fundamental aspects of this area. But first let’s get right down to basics. What is stress? Stress is the amount of internal force that is …

## Amazing materials: Transparent Wood

Transparent wood is a type of a composite material that has the potential to revolutionise the fields of constructionÂ and the manufacturing of various products. It combines the benefits of wood as a material and the achievement of making it opaque. For now,Â transparent wood remains under development but advancements in the science of materials suggest that …