
Description
A straight 13mm connection
A ½-inch BSP male tank connector with a ribbed hosetail for nominal 13mm flexible pipe.
The straight body takes the hose directly away from a suitable water butt or tank wall.
One black plastic fitting, nut and washer. Hose and clips separate.


Match the thread and hose separately
The photograph shows the actual straight connector, back nut and single mounting washer. The male threaded stem fixes at a suitable tank connection; the ribbed hosetail takes matching flexible pipe.
½-inch BSP identifies the tank thread. The hose end is for suitable pipe with a nominal 13mm internal diameter, commonly described as ½ inch. Neither designation gives the outside diameter of the hose fitted over the barb.
½-inch corrugated pond hose is available separately. Check its actual fit on the hosetail and support the pipe so its weight does not strain the connector.
Measure the outside of the assembled hose joint before choosing clips. 12-20mm hose clips are an option where that measured diameter is within their range. Check current suitability and availability before ordering.
Check the space around the outlet
A straight connector needs clearance for the hose beyond the tank wall.
At the mounting surface
Check wall thickness, washer seating and access to the back nut. An existing threaded outlet must match the ½-inch BSP male thread. For a plain opening, check the actual connector and mounting parts before selecting a hole size.
Along the hose
Allow room for the barb and securing clip, then a gentle bend if the route changes direction. Keep the hose supported so movement and pipe weight do not pull on the plastic fitting.
After installation
Lead an overflow to a suitable discharge point and keep its route clear. Check the tank-wall seal and hose connection with water, then inspect both again after the pipe has settled into its final position.
Questions about this connector
Does ½-inch BSP mean a 13mm hole in the tank?
No. BSP is a nominal thread designation, while 13mm here describes the nominal internal diameter of the hose. Check the actual fitting, mounting parts, tank wall thickness and washer seating before choosing an opening. Do not drill from the BSP name alone.
Is this a straight connector or an elbow?
This is a straight connector: the tank thread and hose barb are in line. The attached pipe leaves directly away from the mounting surface, so allow space for the fitting, clip and a gentle bend beyond the hosetail where needed. Check the available clearance before ordering.
What is included in the pack?
You receive one black plastic straight connector, one retaining back nut and one mounting washer. Suitable nominal 13mm hose, securing clips, tools and any additional sealing materials are separate. A two-container linking installation needs compatible connections at both ends.
Can I use it with mains-pressure water?
No pressure rating is specified for this fitting, so do not assume suitability for mains water or a pressurised pump outlet. Those systems need components with confirmed ratings. For a water butt connection, support the hose and check both completed joints with water.
Product information & technical details
| SKU | BUTT12BSPM-12B001 |
|---|---|
| Product type | |
| BSP thread size | 1/2" |
| Thread gender | Male |
| Barb size | 13mm (1/2") |
| Colour | Black |
|---|---|
| Material | Plastic |
| Connection configuration | Straight |
| Supplied mounting parts | Back nut and washer |
| Quantity supplied | 1 straight connector |
What is BSP?
What is BSP thread size?
BSP (British Standard Pipe) is a nominal pipe-thread size, not a direct measurement of a fitting’s bore or outside diameter. For example, a ½-inch BSP male thread measures about 21mm across its outer thread crests.
These figures are approximate outside diameters of male BSP threads, to help identify the nominal size. They are not inch-to-millimetre unit conversions:
- 3/8" BSP → 16.66 mm
- 1/2" BSP → 20.95 mm
- 3/4" BSP → 26.44 mm
- 1" BSP → 33.25 mm
- 1.25" BSP → 41.91 mm
- 1.5" BSP → 47.80 mm
- 2" BSP → 59.61 mm
- 3" BSP → 87.88 mm
- 4" BSP → 113.03 mm
All our BSP threads are parallel (BSPP, to ISO 228), not tapered.
Measure across the outside of a male thread, then check its pitch and whether it is parallel or tapered. Diameter alone does not confirm compatibility. Check the product’s stated thread specification before connecting.
All delivery times are estimates and not guaranteed. Orders placed before 1 pm, Monday to Friday (excluding bank holidays), will be dispatched the same day, while orders placed after 1 pm will be dispatched by the end of the next working day.
If an invalid postcode or address is provided, the order will be cancelled without further notice, as we are unable to modify addresses or print labels for invalid postcodes.
Our standard delivery option is Royal Mail Tracked 48, which typically takes 3–5 business days. If you need your order more quickly, Expedited delivery via Royal Mail Tracked 24 is available, offering a 1–2 business day service.
Large or bulky items may be sent via courier at our discretion and are usually dispatched for next-day delivery. Please note that we only ship to mainland UK addresses; delivery to non-mainland locations, including the Highlands & Islands, may not be available for large or heavy items. If your address falls into one of these areas and you wish to purchase such items, please contact us with your postcode and order details before placing your order. If we cannot ship to you, you are welcome to arrange your own courier for collection.
All products, unless otherwise stated, come with a standard manufacturer warranty against faulty workmanship.
If your product fails within six months of delivery, please contact us with your order reference number, a description of the issue, and clear images illustrating the fault.
Should your item require a return for further investigation, it is your responsibility to arrange and cover postage back to us.
If we are unable to repair the fault, we may offer either a replacement or a full refund.
In cases where the item is inspected and found not to be faulty, or where damage is determined not to be due to manufacturing defects, you will not be entitled to a refund or replacement. We will then either return the item to you via standard post or dispose of it at your request.
You may return any order within 14 days of delivery. As soon as you receive your items, please inspect them carefully, taking reasonable care to keep both the product and its packaging clean and undamaged. If you discover an error or defect after 14 days, we reserve the right to decline your return. If your product fails or breaks after this 14-day time window then your order may be eligible for a warranty claim, please see our warranty information for more details.
To initiate a return, please contact us via our contact form to obtain a return authorisation and the correct returns address (different from the address on your invoice). This can also be done through your 'recent orders' page on your account if you are registered with Shop. Returns sent without prior authorisation will be discarded.
Returned items must be in the same condition in which you received them: unworn or unused, with tags attached and in their original packaging. You must include either a copy of your invoice or a slip with your order reference number inside the parcel. Please be sure not to obscure your return reference number on the label.
If you refuse delivery or reject the parcel without prior notice, we will inspect the returned package and issue a refund upon receipt. Although there is no restocking fee, we will deduct the cost of the return postage label (£3.35) from your refund.
If the returned item or its packaging shows signs of use, damage, or staining, we may deduct up to 50% of the order value, or refuse the return entirely, depending on its condition. Examples include damaged tags, stained, modified or damaged packaging, or missing components.
For faulty, incorrect, or damaged items, please contact us before sending anything back so we can attempt to resolve the issue directly. If we agree that a return is necessary due to our error, we will provide you with a pre-paid return label.
Products that have been modified or damaged through customer action are not eligible for return. This includes, but is not limited to, items that have been cut, trimmed or otherwise altered (such as a tarpaulin or pond liner resized to your specifications), or any product showing damage beyond normal inspection handling.
All delivery times are estimates and not guaranteed. Orders placed before 1 pm, Monday to Friday (excluding bank holidays), will be dispatched the same day, while orders placed after 1 pm will be dispatched by the end of the next working day.
If an invalid postcode or address is provided, the order will be cancelled without further notice, as we are unable to modify addresses or print labels for invalid postcodes.
Our standard delivery option is Royal Mail Tracked 48, which typically takes 3–5 business days. If you need your order more quickly, Expedited delivery via Royal Mail Tracked 24 is available, offering a 1–2 business day service.
Large or bulky items may be sent via courier at our discretion and are usually dispatched for next-day delivery. Please note that we only ship to mainland UK addresses; delivery to non-mainland locations, including the Highlands & Islands, may not be available for large or heavy items. If your address falls into one of these areas and you wish to purchase such items, please contact us with your postcode and order details before placing your order. If we cannot ship to you, you are welcome to arrange your own courier for collection.
All products, unless otherwise stated, come with a standard manufacturer warranty against faulty workmanship.
If your product fails within six months of delivery, please contact us with your order reference number, a description of the issue, and clear images illustrating the fault.
Should your item require a return for further investigation, it is your responsibility to arrange and cover postage back to us.
If we are unable to repair the fault, we may offer either a replacement or a full refund.
In cases where the item is inspected and found not to be faulty, or where damage is determined not to be due to manufacturing defects, you will not be entitled to a refund or replacement. We will then either return the item to you via standard post or dispose of it at your request.
You may return any order within 14 days of delivery. As soon as you receive your items, please inspect them carefully, taking reasonable care to keep both the product and its packaging clean and undamaged. If you discover an error or defect after 14 days, we reserve the right to decline your return. If your product fails or breaks after this 14-day time window then your order may be eligible for a warranty claim, please see our warranty information for more details.
To initiate a return, please contact us via our contact form to obtain a return authorisation and the correct returns address (different from the address on your invoice). This can also be done through your 'recent orders' page on your account if you are registered with Shop. Returns sent without prior authorisation will be discarded.
Returned items must be in the same condition in which you received them: unworn or unused, with tags attached and in their original packaging. You must include either a copy of your invoice or a slip with your order reference number inside the parcel. Please be sure not to obscure your return reference number on the label.
If you refuse delivery or reject the parcel without prior notice, we will inspect the returned package and issue a refund upon receipt. Although there is no restocking fee, we will deduct the cost of the return postage label (£3.35) from your refund.
If the returned item or its packaging shows signs of use, damage, or staining, we may deduct up to 50% of the order value, or refuse the return entirely, depending on its condition. Examples include damaged tags, stained, modified or damaged packaging, or missing components.
For faulty, incorrect, or damaged items, please contact us before sending anything back so we can attempt to resolve the issue directly. If we agree that a return is necessary due to our error, we will provide you with a pre-paid return label.
Products that have been modified or damaged through customer action are not eligible for return. This includes, but is not limited to, items that have been cut, trimmed or otherwise altered (such as a tarpaulin or pond liner resized to your specifications), or any product showing damage beyond normal inspection handling.