Semi metallic Brake Pads are among the most widely used brake pads in the world. They are the preferred types of brake pads in almost every commercial vehicle these days. Read on to know more about these robust brake pads.
A car is a magnificent piece of engineering. The amount of research that goes into the design and manufacture of every minute aspect of a vehicle is mind-boggling. Sadly, not may appreciate the intricacies of this engineering and only have a regard for the final product and their functionality. Take brake pads for example. The primary requirement for an efficient baking system is a firm, yet smooth braking capabilities over a wide temperature range and varied road conditions. Today, auto markets are flooded with a variety of consumer grade brake pads - from organic brake pads and semi metallic brake pads to ceramic brake pads that feature their own set of pros and cons. The choice in material dictates the friction of the pads, which in turn is responsible for the stopping power of the brake pads.
What is a brake pad?
A disc brake pad comprises of friction materials mounted on a sturdy steel backing plate. Each wheel has two brake pads contained in the brake caliper on either side of the rotor, with the friction sides facing the rotor. When the brakes are applied, the caliper squeezes the brake pads so that they contact the rotating rotor, thus slowing down and eventually stopping the vehicle. Over time, these brake pads tend to wear out with use and need to be replaced at regular intervals, as recommended by the manufacturer, to ensure that they maintain a credible degree of stopping power. The disc wear rate varies with the type of material used and the number of miles driven.
A brief history of brake pads
Asbestos was the preferred material of brake pads manufacture during the 1950’s and 60’s when disk brakes began to gain popularity. Asbestos has excellent durability and heat resistance characteristics, which has made it the preferred material of choice. However, as its detrimental environmental and health implications came to light in the 70’s, it was phased out and replaced by safer, more durable materials that were made of organic and metallic compounds.
The organic brake pads are primarily made of glass, rubber and associated “soft” compounds that are fused together with heat resistant resins. These types of braking pads are lighter in weight and are quieter in operation. However, owing to their soft structure, these pads tend to wear out quite fast. Hence, they are suitable for smaller vehicles that do not require frequent hard stops.
Metallic pads, like the name suggests, are made of metals such as iron, copper, steel etc. along with a graphite lubricant. The materials used for the manufacture of this product give it a unique structure and thus makes it one of the most robust types of brake pads today. These types of pads are known to easily dissipate heat from the rotors during braking. This increases the overall life of the entire braking system and requires less frequent rotor replacements. The metallic brake pads are considered to be much better than their organic counterparts in terms of overall performance. Another popular type of brake pads in the markets today are the ceramic pads, which are made of stacked ceramic fibers, bonding materials, and filler materials with trace amounts of metal for added stability.
What are semi metallic brake pads?
Semimetallic brake pads are an amalgamation of both metallic and organic brake pads. They are made of strands of steel, which comprises of up to 35- 60% metal by weight. These metallic stands, which are made of steel, iron, copper, etc., are combined with friction modifiers and a graphite lubricant (and infused in an organic resin) that makes them highly durable. The metallic composition has a high thermal threshold and hence these brake pads have a wider operating temperature range, which results in low compressibility and provides firm braking.
Apart from the efficiency of operation, another factor that is responsible for the popularity of semi metallic brake pads is their cost factor. The compositional materials and manufacturing methods of semi metallic brake pads are not cost intensive, and hence are available at a cheaper price. Since they don’t wear as much as other types of brake pads, they don’t have to be replaced frequently. These pads are extremely versatile and can be used for small cars and large trucks/ SUVs as well. Despite all advantages, these brake pads do come with their own set of problems. The most persistent of them are the noise and the brake dust generated during braking. This material is also quite abrasive, and tends to wear brake rotors faster than organic brake pads.
Comparing with the closest rival- Ceramic brake pads
The tussle between the semi metallic brake pads and the ceramic type has always yielded in ambiguous results. Your choice in either one will always be a compromise- either in terms of longevity or performance. Although the ceramic pads offer cleaner, quieter stops, you will be sacrificing braking performance. While the semi metallic ones offer excellent stopping power, they do result in loud screeches and dust from the eroding pads.
Ceramics are harder than their semi metallic counterparts. This hardness does increase their life, but as they have a lower cold bite, the ceramic brake pads tend to be practically less effective in colder weathers. Ceramics are not very good heat sinks and cannot effectively absorb the heat from the rotors during braking, and contribute to the increase of temperature within the entire braking system. Ceramics also have a lower coefficient of friction and were never designed for high performance action. Semi metallic brake pads, however, offer an excellent stopping power despite the noise and dust. They operate better on a wide range of temperatures due to their higher thermal threshold. They offer a consistent stoppage throughout their wide band of operating range.
Pad selection
Selecting the right braking pad can be quite difficult. The right kinds of pads are not always the most expensive ones. You need to consider various factors such as the weight of the vehicle, acceleration, and the ambient temperature of the place you drive in as well. When in doubt, replace your existing brake pads with factory specified types. This will ensure optimal performance for your vehicle. If you do choose to upgrade your existing pads, then you need to consider the implications and take professional help in choosing and installing the right kinds of brake pads. In most cases, it is recommended that you use high quality, semi metallic brake pads which offer excellent stopping power and fade resistance.
This post first appeared on Semi-metallic Brake Pads – The New Age Replacement Components!, please read the originial post: here
