The best reinforcing steel bars, compared.
Top pick: Generic 8 mm bar, 5 × 1 m Best value: None in this set – The 6 mm pack is the lowest price a metre and sits outside the Eurocode 2 ductility note. The unbranded 8 mm pack says Commercial and has 12 ratings. Updated 23 October 2026.
Reinforcing steel is ribbed carbon-steel bar cast into concrete so the concrete can carry tension. In the UK you buy it as a short posted pack, as a 3 m or 6 m merchant length, or as long mill bar. The usual loose grade is B500B to BS 4449: a characteristic yield of 500 MPa and the middle ductility class. B500A, B500B and B500C share that yield. For work an inspector will see, match the drawing's diameter, name one grade, hold the cover with chairs, and take the lap from the design. A CARES certificate applies when the specification asks for one. Check the variation in the basket with a gauge. T10 and H10 both mean 10 mm high-tensile bar. Self colour is uncoated. Tight rust can be acceptable in concrete. Flaky rust, oil, mud and lost section are not. Bar below 8 mm does not meet the Eurocode 2 ductility note. An A142 sheet is crack-control fabric, not loose offcuts in a footing. Diameter, grade and length are set out in the [reinforcing steel buying guide](/hub/diy-supplies/reinforcing-steel/sub/reinforcing-steel-buying-guide).
Reinforcing steel is ribbed carbon-steel bar cast into concrete so the concrete can carry tension. In the UK you buy it as a short posted pack, as a 3 m or 6 m merchant length, or as long mill bar.
24 products checked · 61 hrs invested · +18,600 readers
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Personal buying guide
Question 1 of 2
What is the job?
The selected title is five 8 mm rods at 1,000 mm for £14.55, sold as Generic with the manufacturer given as Unbranded and the country of origin as China. The grade rating field says Commercial, and this capture has no BS 4449 line, so the listing does not name B500B or B500C. Number of items is 20 against a selected pack of five, and the item weight is 10 kg, while the published mass for 8 mm bar is about 0.395 kg per metre. The amazon.co.uk line is 4.9 from 12 ratings, and the file holds three UK texts, one of which calls them great garden poles. None of those three names rust, a bend, a length error, or a missing bar, which is too small a sample to read as a clean bill. The listing does not describe the bar as stainless or galvanised, and the colour field says grey. A 4.9 on twelve ratings is a thin headline beside a grade field that names no class.
Pros
Cons
Best for: You want five posted 1 m lengths of 8 mm for a garden job and the specification does not name a grade.
Less suitable: A drawing asks for B500B or B500C, a certificate, or a review sample larger than three texts.
Specifications
Common questions
Which pack is selected?
The title selects 5 rods of 8 mm × 1000 mm, and also offers packs of 15 or 20. Number of items is 20, while the selected title says a pack of 5. Unit count is 1.0. The price is £14.55 and the item weight is 10 kg.
What grade is printed?
The grade rating field says Commercial. No BS 4449 line is in this capture. The brand is Generic and the manufacturer is Unbranded. Country of origin is China. The listing does not say the bar is stainless or galvanised. The colour field says grey.
What do the three UK reviews say?
The headline is 4.9 from 12 ratings. The file holds 3 UK texts. One calls them great garden poles. None of the three names rust, a bend, a length error, or a missing bar. That sample is too small to treat the silence as a clean bill.
Ten pieces of 10 mm by 1 metre are listed at £33.48, about £3.35 a metre, with diameter and thickness fields both at 10 mm and item dimensions of 100 × 1 × 1 cm. The part number is RSB081000-10, an 8 mm-style code on a 10 mm title. No BS 4449 line is in this capture, specification met says True with no standard name, and the finish is self colour with natural surface rust described as possible. The headline is 4.8 from 37 ratings, and the file holds eight UK texts that say the size and the lengths were right, with one stated use as railway-sleeper garden steps. None of the eight names rust, a short count, or a wrong diameter, and the reviewers do not mention the part-number code. The item weight is 4 kg, while the published mass for 10 mm is about 0.617 kg per metre, so that weight field does not match ten metres. Eight texts are not the whole of 37 ratings, and the missing grade line still matters if a drawing names B500B or B500C.
Pros
Cons
Best for: You want ten posted metres of 10 mm for a garden step or a similar small job and will gauge the bar yourself.
Less suitable: You need a named BS 4449 grade, a part number that matches 10 mm, or a certificate for a specified pour.
Specifications
Common questions
What size is this pack?
Ten pieces of 10 mm × 1 metre, a 10 metre pack, at £33.48. The diameter and thickness fields both say 10 mm. Item dimensions are 100 × 1 × 1 cm. Item weight is 4 kg.
Does the part number match 10 mm?
The part number is RSB081000-10, which uses an 8 mm-style code on a 10 mm title. No BS 4449 line is in this capture. Specification met says True with no standard name. The finish is self colour, not pointed, and natural surface rust is possible. Country of origin is China.
What is in the review file?
The headline is 4.8 from 37 ratings. The file holds 8 UK texts. They say size and lengths were right, and one stated use is railway-sleeper garden steps. None of the eight names rust, a short count, or a wrong diameter. Reviewers do not mention the part-number code.
Ten pieces of 8 mm by 1 metre are listed at £25.20, with part number RSB081000-10, country of origin China, and an item weight of 4 kg. The diameter and thickness fields both say 8 mm. No BS 4449 line is in this capture. Specification met says True with no standard name, and the finish is self colour, not pointed, with natural surface rust described as possible. The headline is 4.6 from 33 ratings, and the file holds 13 UK texts that mention a concrete pillar, shuttering stakes, a bird-bath pedestal, and a sleeper pond. None of those 13 names a wrong diameter, a short count, or flaking rust, and no reviewer mentions a BS grade or a certificate. Thirteen texts against 33 ratings is only part of the headline. Published mass for 8 mm is about 0.395 kg per metre, so 4 kg on ten metres sits in the same region, unlike the 100 g fields on other Just The Job rows.
Pros
Cons
Best for: You want ten posted metres of 8 mm and can accept a listing that does not name BS 4449.
Less suitable: The drawing names B500B or B500C, or you need a CARES certificate before the pour.
Specifications
Common questions
What is in the pack?
The size bullet says 8 mm × 1 metre, 10 pieces, a 10 metre pack, at £25.20. The part number is RSB081000-10. Country of origin is China. Item weight is 4 kg. The diameter and thickness fields both say 8 mm.
Is a British Standard named?
No BS 4449 line is in this capture. The specification met field says True, with no standard name. The finish is self colour, not pointed, and the listing says it may contain natural surface rust.
What do the UK reviews in the file say?
The headline is 4.6 from 33 ratings. The file holds 13 UK texts. They mention a concrete pillar, shuttering stakes, a bird-bath pedestal, and a sleeper pond. None of those 13 names a wrong diameter, a short count, or flaking rust. No reviewer mentions a BS grade or a certificate.
Just The Job Supplies lists two 10 mm bars at 1,000 mm for £12.26 on amazon.co.uk, and the bullets state BS 4449:2005 Grade B500 B/C with a self-colour finish that is not pointed. The star line is 4.5 from 357 ratings, and the same 50 texts sit on B07NWR8VYY and B07NWQGZB4, so that headline is a parent sample rather than a review of this two-bar variation. Those texts mention 450 mm bars, packs of 20, and a delivery of one bar when the buyer expected two, along with jagged, bent, or twisted ends and rust on arrival. The item thickness field says 8 mm against a 10 mm title, and the item weight is 100 g, which cannot be two metres of 10 mm bar when the published mass is about 0.617 kg per metre. Number of items is 1 while number of packs and the unit count say 2. VAT invoices are offered on request, and no CARES line is printed. The phrase B500 B/C names two ductility classes, so it is not one grade and it is not a certificate.
Pros
Cons
Best for: You need two posted 1 m lengths of 10 mm and will check the diameter with a gauge, accepting a shared review sample.
Less suitable: You need a CARES certificate, one named grade, or reviews that belong only to this two-bar pack.
Specifications
Common questions
What size is the selected variation?
The selected variation is 2 lengths of 10 mm × 1000 mm. The family title also names 8 mm, 10 mm and 12 mm, and lengths of 450 mm or 1000 mm. The item thickness field says 8 mm, which does not match the 10 mm title.
What grade does the listing state?
The bullets say manufactured to BS 4449:2005 Grade B500 B/C. That line names two ductility classes. No CARES certificate is printed. VAT invoices are available on request.
Do the 357 ratings belong to this two-bar pack?
The headline is 4.5 from 357 ratings. The 50 review texts are the same sample as B07NWR8VYY and B07NWQGZB4. They mention 450 mm bars, 10 mm bars, 20 pieces, and a one-bar delivery. They are not a clean sample of this 2 × 10 mm × 1000 mm variation.
This variation is five lengths of 12 mm by 450 mm at £15.32, the only 12 mm pack in the set, and the bullets state BS 4449:2005 Grade B500 B/C with a self-colour finish that is not pointed. Number of packs is 1 and number of items is 10, so the count fields do not agree with a title of five bars. The item weight is 100 g and the thickness field says 8 mm against a 12 mm title. The 4.5 from 357 ratings is the same parent sample as B07NWMKJMY and B07NWR8VYY, including rust on a 45 cm delivery and bent or jagged ends. One reviewer calls 450 mm the right length for log steps, which is a use in that shared file, not a footing size. That 450 mm figure is the bar length, not the foundation depth in Approved Document A. VAT invoices are on request, and no CARES line is printed.
Pros
Cons
Best for: You need short 12 mm lengths, for example log steps, and you will measure the bars rather than trust the thickness field.
Less suitable: You need 1 m stock, a single named grade, a certificate, or a review sample of this 450 mm variation alone.
Specifications
Common questions
What is in this variation?
The selected title is 5 lengths of 12 mm × 450 mm. The family also offers 450 mm or 1000 mm, and packs of 1, 2, 5 or 10. Number of packs is 1 and number of items is 10, so the count fields do not agree.
What finish and grade are printed?
The bullets say self colour, not pointed, and BS 4449:2005 Grade B500 B/C. Item weight is 100 g. The item thickness field is 8 mm against a 12 mm title.
What does the shared review sample say about short bars?
The 50 texts are the same parent sample as the other two Just The Job family ASINs, at 4.5 from 357. One reviewer calls 450 mm the right length for log steps. Others mention rust, bent ends, and one bar instead of two. A complaint may belong to another diameter.
Five lengths of 10 mm by 1,000 mm are listed at £20.45, and the family bullets state BS 4449:2005 Grade B500 B/C, self colour, and not pointed. Number of packs is 5 and number of items is 10, so the count fields do not match a title of five bars. The item diameter field says 12 mm and the thickness field says 8 mm, which puts three sizes on one page. The item weight is 4 kg. The star line is again 4.5 from 357, and the 50 texts match the other two Just The Job family ASINs, including jagged or bent ends and a bar that would not take an SDS driving bit. Treat that headline as the parent listing. B&Q lists five 1 m × 10 mm bars at £17.70, so this amazon.co.uk price is one short-pack option among others. No CARES line is printed.
Pros
Cons
Best for: You want five posted metres of 10 mm and will confirm the diameter, knowing the star line is a family headline.
Less suitable: You need reviews of this variation only, one ductility class on the page, or a certificate for building control.
Specifications
Common questions
Which pack is selected?
Five lengths of 10 mm × 1000 mm, at £20.45. Number of packs is 5 and number of items is 10. The item diameter field says 12 mm and the item thickness field says 8 mm. Item weight is 4 kg.
Is a standard named?
Yes. The family bullets say BS 4449:2005 Grade B500 B/C, self colour, not pointed. VAT invoices are available on request. No CARES line is printed.
Can the 357 ratings be read as this five-bar pack?
No. The file says the 50 texts match B07NWMKJMY and B07NWQGZB4. Treat 4.5 from 357 as the parent listing, not as reviews of this variation alone.
The title quantity is ten pieces of 6 mm by 1 m at £21.73, about £2.17 a metre, with a stated line of BS 4449:2005 Grade B500 B/C. The title and the colour field say Black, while a bullet says a self-colour finish that may have surface rust, and the listing does not describe a coating. Number of packs is 2, number of items is 20, and the unit count is 10.0, so the count fields do not match a title of ten. The headline is 4.5 from 80 ratings, and the file holds 16 texts that mention lawn-edging stakes, a base foundation, a wall joint in a 12 mm mortar bed, and a hi-fi rack. None of those 16 names a wrong diameter, heavy rust, or a short count. The Concrete Centre notes that bar below 8 mm does not meet Eurocode 2 ductility, so a high-tensile phrase on 6 mm is not the same claim as on 8 mm and above. Country of origin is given as the United Kingdom, and the item weight is not given.
Pros
Cons
Best for: You want thin 1 m rods for stakes or a light garden job, and the drawing does not rely on Eurocode 2 ductility.
Less suitable: The specification needs bar of 8 mm or above, one named grade, or a welded sheet such as A142.
Specifications
Common questions
What size and how many bars does the title name?
The title quantity is 10 pieces of 6 mm × 1 m. Pack sizes on the listing are 2, 5, 10, 15 or 20. Number of packs is 2, number of items is 20, and unit count is 10.0.
Why do Black and self colour both appear?
The title and the colour field say Black. The bullet says a self-colour finish that may have surface rust. The listing does not describe a coating.
What grade is stated, and what did the filed reviews use the bars for?
The stated standard is BS 4449:2005 Grade B500 B/C. Across 16 texts in a headline of 80, uses include lawn-edging stakes, a base foundation, a wall joint in a 12 mm mortar bed, and a hi-fi rack. None of those 16 texts names a wrong diameter, heavy rust, or a short count. Item weight is not given.
Shelf prices, stars and review notes are the amazon.co.uk snapshot already stored for these seven listings. Each score is that star line times 20: 4.5 becomes 90 and 4.9 becomes 98. It is not a lab test of yield, ductility, cover or mass. Review-sample size, the stated grade and the price per metre are not inside that number. No listing is a top pick or best value, because the shared 357-rating headline is one parent sample and the highest star line has 12 ratings on a grade field that says Commercial.
Star line
100%The score is the amazon.co.uk star line multiplied by 20. A 4.5 becomes 90, a 4.6 becomes 92, a 4.8 becomes 96, and a 4.9 becomes 98. Stars are the whole of this number. They are not a mill certificate and not a site test.
You are choosing loose ribbed bar to cast into concrete. The seven amazon.co.uk packs on this page are short cuts, from about £12.26 to about £33.48, not 3 m or 6 m merchant lengths. None is a top pick. The score is the star line times 20, three listings share one review sample, and no page prints a CARES line. Match the drawing's diameter and one grade, or leave a specified foundation to building control. A sheet such as A142 is a different product.
Reinforcing steel in this category is loose ribbed carbon-steel bar, cast into concrete so the concrete can carry tension. UK householders usually meet it as a posted pack of 450 mm or 1 m bars. Merchants sell 3 m and 6 m stock. Mills sell long heavy bar. The usual loose grade is B500B to BS 4449, with a characteristic yield of 500 MPa and the middle ductility class. B500A, B500B and B500C share that 500 MPa yield.
Three Just The Job listings show 4.5 from 357, and the filed texts are the same parent sample. They mention other lengths and other counts. That headline is not a review of the variation in your basket.
The line names two ductility classes. It is not B500B alone and it is not a CARES certificate. Commercial names no class. Bar under 8 mm does not meet the Eurocode 2 ductility note because a title says high tensile.
Nominal cover is at least 40 mm on blinding and at least 75 mm cast against soil. Chairs hold it. A lap comes from the design, not from a forum multiple of the diameter. Do not heat a bend, and do not put trolley mesh in a footing.
Diameter is the first check, on the variation in the basket, confirmed with a gauge. One family can span 8, 10 and 12 mm while a technical table repeats another size. T10 and H10 both mean 10 mm high-tensile bar. Then one grade. Prefer B500B or B500C to BS 4449. A line that says B500 B/C names two ductility classes, and it is not a certificate. Commercial names no class. EN 10080 alone does not set the strength. Length and piece count have to match the variation you pay for.
Traceability matters when the job needs it. CARES asks for a certificate, the mill and the batch, and a bundle tag. A path repair may not. A foundation under building control may. None of the seven listings prints a CARES line. VAT invoices on request are not that certificate. Self colour is uncoated and may show tight rust, which the Concrete Society treats as acceptable in concrete. Flaky rust, oil, mud and lost section are not. The bar in this set is not stainless and not galvanised.
Three typical situations, each with a recommendation from this comparison.
You are patching a small pour and you will pay more per metre for a bar that arrives by post. The Just The Job two-bar pack is 10 mm by 1 m at about £12.26, and the bullets state BS 4449:2005 Grade B500 B/C. That line names two classes, the 4.5 from 357 is a shared parent sample, and there is no CARES line. The thickness field says 8 mm.
You are casting a shed base. That job usually needs mesh and building control, not a bag of offcuts. If the drawing still calls for a few 8 mm bars, the ten-piece Just The Job pack at about £25.20 has diameter and thickness fields that both say 8 mm. It does not name BS 4449, and 13 UK texts sit behind 4.6 from 33 ratings. It is not an A142 sheet.
You are buying to a drawing and you want one named grade and a certificate, not a shared star rating. None of these listings prints a CARES line. The five-bar Just The Job variation at about £20.45 states BS 4449:2005 Grade B500 B/C on 10 mm by 1 m, which is two classes, and the item diameter field says 12 mm.
No row in this set is a top pick, and none is best value. The number beside each listing is the amazon.co.uk star line times 20, not a lab test: 4.9 from 12 ratings becomes 98 on the unbranded 8 mm pack, whose grade field says Commercial. Three Just The Job variations share 4.5 from 357 and the same review texts, so that headline is not three results. The lowest price a metre is the 6 mm pack, about £2.17, and bar under 8 mm sits outside the Eurocode 2 ductility note, which is why that price is not an award.
None in this set
The 6 mm pack is the lowest price a metre and sits outside the Eurocode 2 ductility note. The unbranded 8 mm pack says Commercial and has 12 ratings.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources and the amazon.co.uk listings compared on this page. Updated 23 October 2026.
This page contains affiliate links to amazon.co.uk (tag pcuk26-21). If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are the amazon.co.uk figures already stored for this set. This is not a laboratory test of yield, ductility, cover or mass.
