Diamond Blade Selection Guide - Application Help
1. Diamond Blade Selection
1.1 Construction and Contractors
Other guides to follow.
1. Diamond Blade Selection:
1.1 Construction and Contractors
General: Diamond blades work by abrasive, rather than cutting action. Harder materials therefore require the application of the right grade of diamond to abrade the surface. Softer materials can be ‘cut’ using relatively few low grade diamond clusters. This accounts for most of the huge variation in price between different diamond blades of the same size.
Soft Materials: Many building materials are relatively soft. Concrete products such as paving slabs and kerbing can usually be cut with a low cost General Purpose diamond blade. Some materials such as most grades of sandstone are not only soft (except Indian ‘Sandstone’ which can be can be very hard), but are also highly abrasive with large grain structures. These will attack the metal on even the most expensive diamond blades, reducing their useful life. Hence it is sensible not to over-specify the blade as you could waste the expensive diamond you have paid for as the metal around them is eroded away. Good options for sandstone there are the lower priced General Purpose diamond blades, or the double protected Road Slitta blades which are designed to protect against wear.
Hard Materials: Sometimes hard materials are catered for by using soft-bond metal diamond segments. This is designed so that the metal wears quickly to constantly expose fresh diamond, which may be of low grade or in low quantity. Whilst the supplier could claim it will cut hard stone, it may not represent good value with a disappointing life span. For a good life-span, the diamond blade should have a good grade of diamond cluster that will not easily break down. These can then be bonded into a harder metal segment that will resist abrasive wear. Mutli-Slysa Premium diamond blades are a good example.
Some building materials are extremely hard. Long-fired clay products such as fire brick, engineering brick and some paying blocks are examples. These usually require premium diamond blades to cut them effectively. An example is the Brick Slysa Premium which includes a specially sourced natural diamond grade. This has narrow gullets (the gap between segments) to give a low chip cut on hard brick, which is especially important for decorative or highly visible use.
For wide ranging use, including hard stone such as granite and Indian stone, as well as hard brick and blocks investment in a premium multi-purpose diamond blade could well be worthwhile for the time saving, Multi-slysa Premium is aimed at this requirement and also includes the ability to cut ductile metal such as RSJs or scaffolding poles.
General Use: Diamond blades are available with a wide ranging cutting ability at prices which are very affordable. General Purpose diamond blades may be ‘entry’ level, but are ideal for the materials many builders and contractors use. It can be worth avoiding the cheaper ‘DIY’ grade products as these can be time consuming and will quickly glaze up on any medium to harder materials, (we do not sell DIY grade). If you are involved in stone or cut a lot of brick, which can vary in hardness, a blade with wide cutting ability such as Multi-Slysa is ideal. This has laser welded construction for durability as well as turbo style segments, together with a good diamond content, it gives fast cutting performance in most building materials.
Asphalt and Ground Concrete: Asphalt has a very abrasive characteristic. Diamond blades for floor saws usually have some protection against premature abrasive wear of the metal. This is most important where the diamond segments are bonded to the metal disc. An effect known as undercutting can occur where the disc is eroded on the weld and a segment is lost long before its useful life has been used. An asphalt diamond blade therefore usually has one of two methods of protection.
a. 2-3 ‘dropped’ segments which are welded lower into the metal disc resulting in the debris being cleared from the path of the welds of the following segments. Alternatively 2-3 skewed segments which expel the abrasive waste are employed.
b. Tungsten carbide inserts can be employed on the leading edge of the welds. This protects the most vulnerable are of the diamond blade.
Road Slitta diamond blades employ both skewed segments and tungsten carbide inserts to give optimum life.
Ground concrete, often known as green concrete before it is cured, is also highly abrasive, especially in its ‘green’ state. This makes a protected blade ideal for ground saws in this application also. Cured concrete on the other hand, can be quite hard, depending on the aggregates. To cater for these various needs some suppliers offer up to 3 different types of ground saw diamond blades. This can be a nuisance when a variety of surfaces are to be cut for a single task. Consider for instance the installation of a utility from the road main to a factory. The trench will typically need to be cut through the road asphalt, across a pavement, through a car park and into a concrete floor. How many blade changes should the contractor make? A better option is the use of a protected blade for the abrasive materials with a good diamond concentration for the harder concrete aggregates, ie one blade to do the whole job. We offer such a diamond blade in Road Slitta, which is highly popular with contractors for use on both floor saws and hand held petrol saws.
Tile cutting with diamond blades can now be undertaken by two types of method:
- A fixed cutting machine ranging from small DIY tile saws taking blades from 110mm upwards to industrial moving table saws for larger slabs. These are usually wet cutters.
- A hand held angle grinder. These require diamond blades capable of being used dry.
The wide range of tile materials requires different cutting solutions. A standard tile disc blade is suitable for most ceramic tiles. Whilst these have a hard face, the coating is usually thin, with a softer backing material, which makes for relatively easy cutting. The continuous rim of a standard tile blade gives a low-chip cut and would normally require water cooling. Smaller diameters, eg 115mm may be suitable for dry use on an angle grinder, but larger sizes may distort and have diminished lives due to heat if used dry.
Porcelain and glass tiles are usually solid all the way through and can be much more difficult to cut. The standard cutting discs supplied with most machines are not usually suitable for these materials and users may find progress disappointingly slow, whilst the temptation to apply pressure may result in excessive chipping. The best blades for these applications have narrow section so that the abrasive action is more concentrated on a smaller area. They also require a high grade of diamond cluster, which is why these diamond blades are much more expensive . Premium ranges for porcelain and glass include Tile Slysa Premium, a smooth cutting thin blade, and Tile Slysa Turbo Premium, with a ‘turbo’ edged thin blade. This latter design is better for angle grinders as it cools better for dry use. It also has a stiffening flange to minimise risk of flexing, which can be a problem on some tile cutting machines with tilting tables.
Sometime tillers find it easier to clamp the tile and cut it with an angle grinder. This requires a diamond blade suitable for dry cutting. In practice most tile blades of 115mm (standard small angle grinder) will perform OK when dry. Turbo-edged blades are better at self cooling and the Tile Slysa Turbo Premium is ideal for use on angle grinders to cut hard porcelain.