What is a torque wrench used for? Types and selection
When making bolted connections, you often have to rely on your own experience when tightening bolts. Too little torque will cause the nut to come loose. Conversely, applying too much force will shear the bolt while tightening or under load during operation. In such situations it's good to have a torque wrench on hand. It allows tightening bolts with a strictly defined force set on the tool. How does such a device work? What kind of torque wrench is worth buying? And how to use it correctly? We answer these questions in this article.
What is a torque wrench?
A tool used for loosening and tightening bolts and nuts with a strictly defined force is called a torque wrench. It allows selecting the torque according to the manufacturer's specifications. It is most often used to tighten car wheels in such a way that the connection does not loosen while driving, while also protecting the nuts and bolts from being sheared. Its use is also recommended for components working under variable load. The torque wrench is also used in precise connections of aluminum to steel or another aluminum component.
How does a torque wrench work?
The general principle of a torque wrench is to limit the maximum torque with which the bolt is tightened. Depending on the model, the tool will then disconnect, preventing further tightening, or emit an audible signal when the set limit is exceeded. Much therefore depends on which torque wrench we use. The internal construction is, however, quite similar. It is based on a spring whose tension is adjusted by the user. Electronic models also include a strain gauge sensor that reads the current torque. After the setting is exceeded, the mechanism locks or disengages the gear.Does a torque wrench work both ways? In this respect the tool is similar to aratchet wrench. The gears transfer torque in only one direction in the given setting. However, it is easy to change the direction of operation of the tool by turning it or flipping the switch.
Types of torque wrenches
How a torque wrench works is to some extent dependent on its type. Among the most popular solutions you can find:
The most classic solution is the pointer torque wrench. They have an indicator of the resistance that the bolt exerts while tightening. The reading accuracy in this case is up to 4%. Some models have a lock system after the setting is exceeded. It is a simple force gauge that increases control over the torque with which a bolt or nut is tightened.
Mechanical wheel torque wrench. Also called a click wrench. The spring inside bends under load, and after the set force is exceeded it releases a pawl that locks the tool. At that moment a characteristic click is heard, signaling that the bolt is properly tightened. Individual models allow setting torque from 20 to 200 Nm.
The hinged (breaking) torque wrench is equipped with a special hinge that releases when the torque exceeds the setting on the device. Then the tool bends at an angle of 20 degrees, preventing further tightening. After removal, the wrench returns to its initial position and is ready for the next use.
The modern, good electronic torque wrench is equipped with an LCD screen showing the currently used force. Measurement accuracy can range from 0.5% to 4%. After exceeding the set value, an audible signal sounds and pawls cut off the possibility of further tightening. An additional useful function is the memory of several basic settings.
Which torque wrench for the engine and which to choose for fastening car wheels? Each of the types listed will work equally well for any task. However, there are also specialized models with a narrow range of applications.Torque wrench for valves with a maximum torque of 0.45 Nm protects metal and rubber valves from damage during screwing.
How to use a torque wrench?
You already know what a torque wrench is, how it works and what types you can encounter. But how to apply the knowledge in practice? First you must choose the right size of the tool.1/4'' torque wrench has a square of size 1/4 inch. It is the element connecting the device with interchangeable sockets of various sizes, which should be matched to the size of the bolt. You can encounter three most popular drive sizes: 1/4 inch is suitable for precision work with socket sizes up to 13 inclusive. The 3/8 inch square is used for standard car work. For the heaviest jobs choose a 1/2 inch or 1 inch wrench.Next you must choose the proper ratchet rotation direction and the maximum tightening torque. Finally you can begin work. We have already written abouthow to use a torque wrench in another article of ours.
Which torque wrench to choose?
Before buying, it's worth considering what a torque wrench is for? It is most often associated with tightening car wheels, but it is also always used when assembling an engine block. To properly carry out such a process, it is necessary to repeatedly tighten bolts with a specified torque. The slightest mistake can result in gasket damage. That is whythe torque wrench is an indispensable work tool in this case. On the other hand it is also useful in the home workshop if you want to avoid the risk of shearing bolted connections. It is also useful when repairing a bicycle or other household equipment.Which torque wrench should you choose? It's worth opting for durable models made of chrome-molybdenum steel, made by reputable manufacturers. They are characterized by high strength and hardness, while also being corrosion-resistant due to the high chrome content. Before buying, be sure to check the range of torque offered by the given torque wrench. Professional equipment often offers a smaller range with greater measurement accuracy. Our staff, who have extensive experience using such tools, can also advise you. They will gladly suggest which solution will be best in your case.
Car warning vest should be in every vehicle – in case of a breakdown it will allow the driver standing next to the vehicle to remain visible even after dark. However high-visibility vests are also an essential piece of equipment for construction workers, road workers and many other jobs. Check what to consider when buying a warning vest!
Is a warning vest mandatory?
A warning vest is an inexpensive item of clothing that everyone should have. It is useful not only in the car, but also when cycling after dark or even as protection for a pedestrian walking on the roadside.
Do you have to have a warning vest in the car? Polish regulations do not impose such a requirement on drivers. They indicate, among other things, the need to have a reflective triangle and a fire extinguisher. Although you won't get a fine for not having a warning vest, it is definitely worth having one. If you often travel with passengers, it's best to equip yourself with reflective vests in quantities sufficient to provide visibility to passengers if needed.
Reflective warning vest – a requirement in many professions
While a high-visibility vest for a motorcycle, bicycle or car is not required by regulations, in some professions it is. Professional high-visibility clothing is a necessary part of the wardrobe for airport workers, heavy equipment operators, construction workers, and people performing official duties on roads or in railway areas.
As for warning vests, regulations in 2023 require them to be one of three colors: yellow, orange or red. In addition to fluorescent colors, they must also have reflective elements.
High-visibility clothing is divided into class one, two and three. In the case of warning vests only classes one and two are possible, because class three requires reflectors on the sleeves or trouser legs. Such a standard is met, for example, by warning jackets.
A class one high-visibility vest must have 0.14 m2 of fluorescent background, while the total area of reflective elements must be 0.10 m2. For class two these values are 0.50 m2 and 0.13 m2 respectively. A professional class 2 vest is ORLA Warning Vest. Available in two colors – orange and yellow, it meets EU standards EN ISO 20471 and EN ISO 13688. Two reflective strips 5 cm wide provide visibility, and the anatomical fit guarantees comfort of use of the reflective warning vest both during work duties and while traveling by bike, motorcycle or on foot.
Summer and winter warning vest to suit your needs
When choosing a reflective warning vest for pedestrians, cyclists or motorcyclists, pay particular attention to its size and the quality of the material. Contrary to appearances, fit is very important – especially if you will be wearing the vest for a long time. This type of body-protecting clothing is available in standard sizes – from S to 3XL. Importantly, these products are not divided into men's and women's high-visibility vests – they are universal garments with a simple cut.
In cold months, an insulated work warning vest will provide protection against cold, wind and precipitation. The REMS insulated warning vest model has a warm inner layer. An additional convenience is a zipper closure instead of traditional Velcro. This solution allows better protection against low temperatures and weather conditions. The REMS warning vest also has two inner pockets that allow for storing accessories useful at work.
How much does a reflective warning vest cost?
Purchasing a reflective PPE vest will not usually ruin the household budget of someone who wants to be visible while cycling or to have such important protection in the car.
You can also find much cheaper products in stores and at online auctions. Do yellow and orange reflective vests for 4–5 PLN differ from those from a trusted manufacturer costing a dozen or so zlotys? Although they may look the same at first glance, you will notice the difference in how long the product lasts. The reflective warning material on high-quality vests is much more durable – it retains its shape after many wash cycles. Meanwhile, cheap reflective vests often lose their properties after just 2–3 washes.
So if you don't want to spend two years wearing a vest that has never been washed, choose a higher-class product. Quality matters especially when you buy reflective warning PPE vests for your employees.
Of course you'll pay more for an insulated warning vest with pockets. For the aforementioned REMS model you'll pay 166 PLN. In this case, however, you should particularly take quality into account. A vest of poor quality, made of non-breathable material, will cause significant discomfort during work. It is definitely better to opt for products from a trusted warning vest manufacturer.Author: Paweł Sokołowski
WHAT IS THE CE MARK?
The CE marking (Conformité Européenne) is the European conformity mark. Its use on a product's packaging indicates that the manufacturer has applied and fulfilled the relevant requirements contained in European directives/regulations, as well as in the European standards covering the product. A product that meets safety requirements will be marked with the CE mark, thereby informing the user that it is safe and has been properly placed on the market.WHY WAS IT INTRODUCED?
After the European Union removed trade barriers between Member States and established a common policy toward partner countries outside the EU, an area of free movement of goods was created within the Community. However, the main barrier to trade remained national requirements concerning, for example, the quality and safety of products. The national systems of regulations and standards used by countries often differed significantly from one another. This caused a range of problems for manufacturers who, in order to sell their product in different countries, had to meet separate requirements each time.
Because consumer safety could not be compromised by eliminating standards, the only solution was to harmonize national systems so that goods would be subject to the same requirements throughout the Community.
In 1993, European legal acts called NEW APPROACH DIRECTIVES were created at EU level. They defined essential safety requirements for different groups of products that must be met before they can be placed on the market or put into service on the Single European Market.
IS CE MARKING MANDATORY OR VOLUNTARY?
if a product falls under one of the New Approach Directives, CE marking is mandatory.
applying CE marking to products that are not subject to the New Approach Directives is prohibited.
WHO CAN AFFIX THE CE MARK?
CE marking may be affixed by the manufacturer or their authorized representative. Most products fall under Module A, i.e., the manufacturer's self-assessment module. If another module applies (B or D), an EU type-examination certificate must be obtained in cooperation with a notified body (a certifying institute).
WHAT IS A CE CERTIFICATE?
The term "CE certificate" does not exist in the nomenclature of the New Approach directives. If someone talks about a CE certificate, they most likely mean the EU declaration of conformity or the EU type-examination certificate confirming the product's conformity with the relevant EN standard.
Currently, the process of marking and certification is regulated by Regulation (EU) 2016/425 of the European Parliament and of the Council of 9 March 2016 on personal protective equipment and repealing Council Directive 89/686/EEC.
Source: https://www.oznakowanie-ce.plAuthor: Grzegorz Nowak
In 2022 as many as 66,606 occupational accidents were reported in Poland. 365 of the injured suffered very serious injuries, and the number of fatal accidents amounted to 180. In almost 80% the lower or upper limbs were injured. Among the most common causes was contact with a stationary or moving object. These data clearly indicate how important it is to provide employees with appropriate protective clothing.
Differences between protective clothing and workwear
To begin with, it is worth dispelling an important mistake. The term „occupational protective clothing (PPE)” and “workwear” are often used interchangeably. However, they do not mean the same thing. To fully answer this question, it is useful to know the exact definitions of both concepts.
Definition of workwear and protective clothing
Workwear is clothing used in the workplace when there is a high risk of soiling or damaging outer garments. In other words, workwear replaces the employee’s clothing in situations where it may become dirty or ruined while performing duties. The use of uniform work outfits may also be related to building brand recognition (e.g., bank or insurance company employees).
And what is protective clothing? The definition states that it is clothing used in the workplace that is intended to cover or replace personal clothing. In addition, it is designed to provide protection against hazards. Both conditions must be met, so workwear that does not protect against specific dangerous substances or events is not protective clothing.
Applications of workwear and protective clothing
When is protective clothing used? Examples of such situations can be found in every industry. It is most often used by employees on production floors and those working in the field, and its purpose is to protect against impacts and cuts (such as protective boots with a steel toe cap). There is also protective clothing for welding and heavy aprons for laboratory technicians who come into contact with hazardous substances.
Work clothes are used even more frequently. They can be found in organizations that care about brand recognition linked to employee attire. Work uniforms are also widely used in the catering industry.
Types of protective and work clothing
Any clothing can be divided according to the part of the wardrobe it represents: protective or work gloves, trousers, jackets, boots or vests. It is worth paying more attention to the classification of protective clothing depending on the hazard it is meant to protect against. In this context, one can list:
Protective clothing for welders, protecting against electric arc, burns and splatter.
Harnesses related to working at heights.
Insulating protective clothing, used by electricians.
High-visibility clothing, protecting road workers, as well as emergency services operating at the scene of a road accident.
Chemical protective clothing, resistant to short-term exposure to hazardous corrosive substances.
Protective earmuffs that protect against excessively loud equipment noise.
Flame-resistant protective clothing for firefighters and people working near open flames.
Additionally, categories of protective clothing may also concern seasons, such as winter and summer protective clothing.
Protective clothing markings
Types of protective clothing can also be characterized by the areas of the body they are meant to protect.
Protective clothing (symbol U).
Lower limb protection (symbol N).
Upper limb protection (symbol R).
Head protection (symbol G).
Face and eye protection (symbol T).
Hearing protection (symbol S).
Respiratory protection (symbol D).
Protection against falls from height (symbol W).
Full body insulating protection (symbol I).
So how to choose the appropriate protective and work clothing for your workplace? That is always the employer’s responsibility!
Employer's obligations regarding protective and work clothing
Under current labor regulations, the employer is obliged to provide the employee free of charge with workwear, protective clothing and personal protective equipment (PPE) if required by the working conditions. Importantly, the decisive factor is the conditions prevailing in a given work environment, not, for example, the job title. For this reason, employees in similar positions at different companies may receive a different set of clothing.
Protective clothing is the employer's obligation
The employer must determine what professional workwear and protective clothing are needed for each employee. This usually takes place during a dialogue with employees or their representative. These arrangements are then entered into the work regulations, which define the conditions for being in the workplace, as well as equipping employees with tools, materials, protective and work clothing and personal and hygiene protective equipment. Typically the details are presented as a protective clothing allocation table for each position.
Work clothing and footwear provided by the employer
Work and protective clothing are provided free of charge. At the same time, they remain the property of the employer. This means that upon termination of employment, all personal protective equipment and allocated clothing must be returned to the supervisor. Also, in the event of clothing being destroyed due to the employee’s fault, reimbursement of the purchase costs is required (after accounting for depreciation).
Employer's duties regarding employee safety
The employer’s duties related to protective clothing and workwear also include cleaning, maintenance, repair, dust removal and disinfection. However, employees often wash their work clothes themselves. In such cases they are entitled to reimbursement of the costs they incur.
Standards and certifications of workwear and protective clothing
Workwear does not require certification, because its primary task is to protect personal clothing from dirt or damage. However, specialist protective clothing for workers must meet specific standards and criteria in order to effectively protect against hazards in the workplace.
Clothing materials: what determines their protective properties?
Protective garments are made from natural materials (cotton), regenerated (cellulose-based) and synthetic materials (polyester or polyamide). From these, several dozen popular materials with specific properties have been developed. Among them you can find:
Ortalion made from polyester. It is characterized by very low weight and high resistance to damage.
Fleece, a soft and warm polyester knit.
Stretch, i.e. stretch fabrics with added Lycra or PBT.
Corduroy, a warm cotton fabric resistant to cuts and tears, but prone to abrasion.
Ballistic nylon, also used in the production of bulletproof vests. It is very resistant to damage and abrasion.
Kevlar, an elastic material that is also extremely durable.
The choice of the appropriate material depends on the work environment and the conducted occupational risk analysis.
Certification by EN ISO standards: what does it mean for protective clothing?
In Poland, EU Regulation No. 2016/425 of 16 March currently applies. It specifies a number of standards for particular types of protective and specialized clothing. It is there that the exact parameters that protective clothing for firefighters, welders and other positions must meet are defined.
All protective garments must also have certificates confirming compliance with the above standards. To obtain them, clothing undergoes rigorous laboratory tests, which must then be repeated at regular intervals.
Summary: protective and work clothing
There are still many workplace accidents in Poland. To provide employees with the best possible protection, protective clothing and personal protective equipment are used in accordance with the protective clothing allocation table. Each such garment must meet protective clothing standards, confirming protection against hazards in the working environment.
In many positions, an employee also receives workwear that protects personal clothing from damage or soiling. In this case, there is no need to obtain certifications.
Both workwear and protective clothing belong to the employer, who should care for them: clean, repair and maintain them.Author: Grzegorz Nowak
