Quick Answer: Genuine insulating gloves carry permanent marks: the double-triangle symbol with IEC 60903 beside it, the class, the category where it applies, and a traceable date or lot. Match the class colour to the class number. Reject any pair that shows only a marketing voltage. This is how to check insulating gloves in about two minutes. Buy only from an electrical hand gloves supplier India trusts, one who shows these marks before you pay.

Introduction

A safety manager opens a carton of gloves. The rubber looks clean and thick. The label says “11000 V.” Nothing else on the glove tells him who made it, when, or to which test.

He has a problem. Rubber looks the same whether a lab tested it or not.

At Thunderbolt Electromech India Pvt. Ltd., we work as an Electrical Hand Gloves Supplier for plants, utilities and contractors across India. We are also a Delhi-based electrical hand gloves supplier, and Old Delhi buyers walk into our shop and ask the same question every week: “How do I know these are real?” This guide answers it. You get a marking checklist, the full class table, the category letters, the colour code, the red flags, and a receiving routine your store team can run without special tools.

If you want the wider buying picture first, read our complete electrical hand gloves buying and safety guide.

Why an Electrical Hand Gloves Supplier Must Show Marking, Not Just Voltage

A glove is not a product that proves itself. You cannot judge insulation by thickness, feel or smell. The only evidence is a chain: a standard, a type test, a production test and a mark that links the pair in your hand to that test.

The marking is that link. Without it, you buy a promise.

What the double triangle actually says

The double-triangle symbol tells you the glove was made for live work. The standard number beside it tells you which rulebook the maker claims to follow. Next comes the class, which fixes the voltage the glove may handle. Each mark answers one question a safety officer must ask before a worker slides a hand inside.

A pair with the symbol but no standard number is half an answer. A pair with a standard number but no class is worse. The worker cannot tell which job the glove suits.

Why “marketing voltage” is a weak signal

Many cartons print numbers such as “1100 V,” “11 kV” or “33 kV” in bold. Those numbers tell you very little.

Consider what they leave out. Is the number a test voltage or a working voltage? Is it AC or DC? Is it phase-to-phase or phase-to-earth? Which class does it match? A glove tested at 10 kV AC and a glove allowed to work at 10 kV AC are two very different objects.

Here is the engineering point most buyers miss. In the IEC system, each class has a proof test voltage and a lower maximum use voltage. The gap between them is the safety margin. A bare “11 kV” claim hides which side of that gap the number sits on.

The cost of a wrong glove

Insulating gloves sit between a worker and current. They fail rarely, and a failure costs a great deal. A mislabelled pair can look perfect for years and fail on the one day it matters. Marking will not stop every defect. It does move most of the risk from the worker to the supplier, where it belongs.

Electrical Hand Gloves Supplier Checklist: Seven Marks on Every Genuine Pair

Print this section. Tape it above the receiving bench. Check every pair against it before it enters stores.

Mark 1: The double-triangle symbol

Look at the cuff area. You should see the double-triangle symbol, moulded or permanently marked. It should stay clear when you rub it with a thumb. Ink that smears or peels is a bad sign.

Mark 2: The standard reference

The reference “IEC 60903” should sit next to the symbol. Read the number carefully. Counterfeit marks sometimes show a standard that covers a different product. A summary of the standard confirms that the number goes beside the symbol, so a stray reference elsewhere does not count.

Mark 3: The class

The glove must show its class: 00, 0, 1, 2, 3 or 4. The class sets the maximum use voltage. No class means you cannot match the glove to the job. Reject it.

Mark 4: The category, where it applies

Categories describe extra resistance. A glove may carry A, H, Z, R or C, or none at all. Where a category is claimed, it must appear in the marking. We explain each letter later in this guide.

Mark 5: The class colour

Gloves often use a colour label to show the class. Check the colour against the class number. The usual colour list is: 00 beige, 0 red, 1 white, 2 yellow, 3 green and 4 orange. Confirm the colours against the current edition of the standard, because summaries differ. A red label on a glove marked Class 2 is a mismatch. Stop and ask why.

Mark 6: Maker and size

A traceable pair names its maker or trademark. It also shows a size. If you cannot tell who made a glove, you cannot ask who tested it.

Mark 7: A traceable date or lot

Look for a manufacture date, a batch number or a lot code. Some makers print a serial or a flashcode. CATU gloves, for example, carry a flashcode for traceability. Whatever form it takes, the code must let the maker trace the pair back to its production test.

Without that code, a complaint goes nowhere.

How to run the checklist in two minutes

1. Pick a pair from the carton. Do not trust the box alone.
2. Find the symbol and the standard number.
3. Read the class. Match it to the colour.
4. Read the category, if present.
5. Find the maker, size and date or lot.
6. Log the lot number against the purchase order.
7. Accept, hold or reject.

That is how to check insulating gloves without a laboratory. The routine catches most bad pairs before they reach a worker.

Electrical Hand Gloves Supplier Guide to All Glove Classes

IEC 60903 sorts insulating gloves into six classes. The class decides the voltage range. Choose by the highest voltage your worker can touch, then add margin as your site rules require.

Class	Colour label	Proof test voltage (AC)	Maximum use voltage (AC)	Typical use
00	Beige	2,500 V	500 V	Low voltage panels, control circuits, appliance work
0	Red	5,000 V	1,000 V	Low voltage distribution boards, motor control centres
1	White	10,000 V	7,500 V	Distribution up to about 6.6 kV systems
2	Yellow	20,000 V	17,000 V	11 kV and 15 kV class work
3	Green	30,000 V	26,500 V	22 kV and 25 kV class work
4	Orange	40,000 V	36,000 V	33 kV class work

Please verify these values against the current edition of the standard before you write them into a procedure. Maximum use voltages for direct current run higher than the AC values.

Class 00: the light work glove

Class 00 gloves are thin and flexible. They suit electronics, control panels and low voltage tasks where touch matters. Electricians who need to feel a small screw prefer them. They are not made for distribution boards that carry heavy fault energy.

Class 0: the everyday glove

Class 0 gloves cover work up to 1,000 V AC. They are the usual choice for factory distribution boards and motor control centres. Most maintenance teams in light industry live in this class.

Class 1: medium voltage entry

Class 1 gloves step up the protection. They suit work on systems up to the low kilovolt range. The material gets thicker, and dexterity drops a little.

Class 2: the 11 kV workhorse

Class 2 gloves fit the voltage range many Indian utilities and industries use for primary distribution. Because 11 kV is so common, this class sells in volume. It is also the class most often faked or mislabelled.

Class 3: higher voltage work

Class 3 gloves suit 22 kV and 25 kV class work. They are heavier and stiffer. Teams who use them train for grip and control.

Class 4: the top of the range

Class 4 gloves handle the highest standard class, up to 36 kV AC maximum use. They are the thickest glove in the range. Specialist crews and large substations use them.

Why the thickness limit matters

The standard sets a maximum thickness for each class. The limit exists for a reason. A glove that is too thick loses dexterity, and a worker who cannot grip a tool safely takes more risk. Class 00 allows about 0.5 mm. Class 4 allows about 3.6 mm. If a supplier claims a high class on a thin, flimsy glove, something is wrong. If a glove is far thicker than its class limit, it may be built to a heavier rule or poorly made.

A short note on direct current

Solar plants, battery rooms and traction systems use DC. Maximum use voltages for DC run higher than AC values for the same class in the standard. Do not borrow AC figures for a DC job without checking the table. Our electrical hand gloves category page lists the pairs we stock, so you can match class to circuit.

Categories: What the Letters A, H, Z, R and C Mean

The class tells you the voltage. The category tells you what else the rubber can survive.

Category	Resistance claimed	Where it matters
A	Acid	Battery rooms, chemical plants
H	Oil	Transformer yards, workshops, hydraulic areas
Z	Ozone	Outdoor work, high-voltage lines, hot and sunny regions
R	Acid, oil and ozone together	Mixed environments
C	Very low temperature	Cold regions, winter outdoor work

A glove with no category letter is not faulty. It simply makes no extra claim. Do not use it in an environment where oil or acid is present.

Why category matters for engineers

Insulation rubber is a polymer compound. Oil swells many rubber compounds. Acid attacks the chain structure. Ozone cracks stretched rubber along the fold lines. Each category letter says the maker tested the glove for that attack and it passed the tests.

For a transformer yard in Delhi’s summer, category Z deserves a place on your shortlist. Heat, sun and ozone together age rubber faster than most buyers expect. For a battery room, look at category A.

Genuine vs Doubtful Gloves: A Quick Comparison

Feature	Genuine pair	Doubtful pair
Double-triangle symbol	Clear, permanent, on the glove	Missing, faint or printed on the box only
Standard reference	IEC 60903 beside the symbol	Absent, or a different standard
Class	Printed on the glove	Only a voltage number
Colour label	Matches the class	Mismatched or missing
Category	Shown where claimed	Claimed in the brochure, not on the glove
Traceability	Date, lot or serial	None
Maker	Named	Not named
Test paperwork	Available on request	“We will send later”
Packaging	Consistent print, clean cuffs	Smudged print, mixed batches

If a pair shows two or more doubtful signs, hold the whole lot. Call the supplier. Ask for the test certificate and the lot record.

Engineering Notes Most Glove Guides Skip

Most articles repeat the class table and stop. Here are four points that matter more on a real site.

Proof test is a pass-or-fail check, not a rating for work

During production, makers apply a proof test voltage for a set time. The glove must not break down. That test is not the voltage you work at. Maximum use voltage sits lower, as the table shows. Treating the test number as a working limit removes your safety margin.

Leakage current counts

Besides breakdown, the standard limits leakage current during the test. A glove can survive the voltage and still leak too much. Leakage rises when the rubber is thin, contaminated or damaged. A properly marked glove has passed this check. A glove with no marks has no record of it.

Gloves age, even in a cupboard

Rubber hardens and cracks with time, light and ozone. A pair stored in sunlight, near a welding bay or beside a transformer can degrade within a season. Many utilities retest gloves at fixed intervals, often every six months. Follow your own rule. A retest date written on the cuff turns storage into a controlled process.

The protector glove question

Insulating rubber gloves are soft. Leather protectors go over them to prevent cuts and punctures. Buyers sometimes treat the protectors as a substitute for class marking. They are not. The protector guards the rubber. The rubber guards the worker. Check the marks on the rubber glove itself.

Customer Problems and Solutions

Problem: The carton says “11 kV” but the gloves carry no class.

Cause: The number is a sales claim.

Solution: Ask the supplier for the class, the test certificate and the lot record. Hold the carton until you get them. If nothing arrives, return the lot.

Problem: Class colour and class number do not match.

Cause: A labelling error, a repack or a counterfeit.

Solution: Reject the pair. Report the lot to the supplier in writing.

Problem: Store staff cannot tell which pair belongs to which purchase.

Cause: No lot logging.

Solution: Record the lot or date code against each purchase order. Tag each pair with its issue date and retest date.

Problem: Workers pick the wrong class.

Cause: Nothing at the point of issue tells them which class suits which job.

Solution: Put a class chart beside the issue counter. Colour-coded bags help.

Problem: Gloves pass a quick look but fail an air test.

Cause: Pinholes or cuts from storage or handling.

Solution: Run an air inflation check before each use. Roll the cuff, trap the air and check for leaks. Discard any pair that fails.

Problem: A tender asks for “IEC 60903 gloves” and quotes arrive at very different prices.

Cause: Not every quote is for the same product.

Solution: Ask each bidder for a marked sample and a certificate. Compare like with like.

Real Use Cases

Substation maintenance team

A substation crew works on 11 kV switchgear. They need Class 2 gloves. The store manager checks each pair for the symbol, the standard, the class and the yellow label. He logs the lot. Every worker draws a pair from a numbered bag with a retest date.

Factory electrical maintenance

A packaging plant runs 415 V motor control centres. The electricians choose Class 0 gloves. Marking tells the purchase team that the pair suits the job. The plant stores the gloves in a closed cupboard, away from sunlight and oil.

Solar and battery installation

A solar contractor works on DC strings and battery banks. The team checks the class and the DC rating in the standard. For battery rooms, they also look for category A, since acid fumes are present.

Contractor mobilising to a new site

A contractor arrives at an unfamiliar site with a mixed stock of gloves. The site safety officer checks every pair. Unmarked gloves stay in the van. The contractor buys marked pairs the same afternoon from a local shop.

Training institutes

An ITI workshop buys gloves for apprentices. Students learn to read the marking before they learn to use the glove. The habit lasts through their careers.

Case Study: A Carton That Looked Right and Was Not

This case study is a composite drawn from patterns we see across industrial customers. We changed details and removed names. Replace it with a signed example from a real Thunderbolt customer if you have one.

A manufacturing unit near Delhi needed twenty pairs of gloves for its 11 kV yard. The purchase team found a quote well below the usual price. The carton said “11 kV tested.” The gloves were yellow. Nobody on the team looked further.

Six weeks later, a new safety officer joined. On his first walk through the store, he picked up a pair and turned it over. The cuff showed no standard number. No class. No lot code. A faint triangle sat near the cuff, with nothing beside it.

He sent four pairs to a test lab. Two of four failed the proof voltage for the class the work needed. Because the plant had issued some of them to the crew, the incident went into the safety log as a near miss.

The corrections were simple:

• The plant withdrew every pair from the lot.
• Purchase added a marking checklist to its goods receipt form.
• The store required a lot code and a test certificate for every glove order.
• Class colour charts went up at the issue counter.
• The plant set a retest date on the cuff of every pair.

The loss was about the price of the gloves. The lesson was bigger. The yellow colour had made everyone feel safe. Marking would have shown the problem on day one.

How to Inspect Gloves on Receipt

Marking proves paperwork. A hands-on check proves the rubber.

1. Visual check. Open the glove under bright light. Look for cuts, pinholes, bubbles, embedded particles and uneven thickness.
2. Stretch check. Gently stretch a small area and look for cracks.
3. Air test. Roll the cuff to trap air. Squeeze the glove and listen for leaks. Hold it near your cheek.
4. Marking check. Run the seven-mark checklist above.
5. Log. Record the lot, the date received and the retest date.

Browse the other posts in our electrical hand gloves cluster for more on the pre-use inflation check.

Ten Questions to Ask Before You Place an Order

A good supplier answers these without hesitation. A weak one changes the subject.

1. Which standard does this glove follow, and which edition?
2. Which class and category is each model?
3. Can I see the marking on a sample pair, not a photo?
4. What is the proof test voltage, and is it AC or DC?
5. Can you share the test certificate for this lot?
6. How does the date or lot code link back to the maker?
7. What is the stated shelf life, and how do you store stock?
8. What size range do you hold?
9. What happens if a pair fails in my own test?
10. Who do I call after the sale?

Write the answers into the purchase order. A clear order leaves less room for substitution at delivery.

Writing a tender clause that works

Many tenders say “insulating gloves, 11 kV.” That wording invites trouble. Name the standard, the class, the category, the size range and the documents you expect with each lot. Add a line that says unmarked or mismatched pairs will be rejected at the gate. Suppliers who sell genuine stock welcome that clause. It removes the unmarked competition.

A word on price

Genuine gloves cost more than unmarked ones because testing costs money. Each production lot goes through a proof test, and the maker keeps records. When a quote sits far below the rest, ask what was left out. Usually the answer is the test, the paperwork or both.

Frequently Asked Questions

Does IEC 60903 apply in India?

Many Indian buyers specify IEC 60903 gloves in tenders. India also has its own standard for rubber insulating gloves. Check which standard your site or client requires.

Can I trust a coloured label alone?

No. The colour supports the class mark. It does not replace it.

What if a glove shows Class 2 but no category?

It is a Class 2 glove with no extra resistance claim. Use it where oil, acid and heavy ozone are absent.

How often should I retest gloves?

Follow your site rules. Many utilities use a fixed interval, often six months, and retest again after any suspected damage.

Can I repair a punctured glove?

No. Discard it.

Should I wear cotton liners?

Many workers wear thin liners for comfort. They must be clean and dry.

Buy from an Electrical Hand Gloves Supplier in Delhi: Thunderbolt Electromech

Thunderbolt Electromech India Pvt. Ltd. is a leading Electrical Hand Gloves Supplier with stock of Raychem, Vidyut and crystal electrical hand gloves. You can see the range on our electrical hand gloves product page and across the full electrical hand gloves category.

Before you order, tell us:

• the voltage and whether the circuit is AC or DC
• the environment: oil, acid, sun, cold
• the quantity and delivery location

We will recommend the class, the category and the right size. Ask for the marking details on the pair, because a supplier who hides them is not one to buy from.

Safety signage, too

Gloves protect hands. Signs protect people from walking into danger. If you are fitting out a panel room or substation, ask us about a danger plate supplier who can match your signage to your gloves order. We supply a powder coated danger plate, an aluminium danger plate and a danger plate for substation use, so you can finish the safety package in one visit.

Trust and Contact Block

Thunderbolt Electromech India Pvt. Ltd. Electrical hand gloves supplier Delhi | Electrical gloves supplier Delhi NCR | Tested gloves Delhi

• Address: Ground Floor, Electrical Market, 1743/46, Ram Gali, Old Delhi, Bhagirath Palace, Chhippy Wada, Chandni Chowk, Delhi, 110006
• Phone: +91-9911886655
• Email: info@thunderboltelectromech.com

Visit us in Old Delhi, call, or write. Bring your tender wording, and we will help you match it to the right class.

Electrical Hand Gloves Supplier: Conclusion

Genuine insulating gloves prove themselves through marking.

Here is the whole blog in brief. A glove cannot show its insulation by look or feel. The marks link the pair in your hand to a standard, a class and a test. The seven marks to check are the double-triangle symbol, the IEC 60903 reference, the class, the category where claimed, the class colour, the maker and size, and a traceable date or lot. The six classes run from 00 to 4, with proof test voltages from 2,500 V to 40,000 V AC and lower maximum use voltages. Categories A, H, Z, R and C describe acid, oil, ozone, all three together and low temperature resistance.

Reject any pair that shows only a marketing voltage. Check the colour against the class. Run a visual check and an air test on receipt. Log every lot. Set a retest date on the cuff and follow your site rules.

Why choose Thunderbolt Electromech India Pvt. Ltd.? We are a Delhi-based Electrical Hand Gloves Supplier with Raychem, Vidyut and crystal gloves in stock. We show you the marks before you pay. We help you pick the right class and category for your site. We also supply danger plates for the same job. You can reach us by phone, email or in person at our Old Delhi shop.

Ready to buy or compare? Visit our electrical hand gloves category, read the complete buying and safety guide, or call +91-9911886655. Email info@thunderboltelectromech.com. We will help you protect your crew.