Tesco Steel & Engineering forges elbolets — the olet family's answer to the one place a normal outlet cannot sit: the back of a 90° elbow. The base is machined to the bend's compound curvature — a saddle curved in two directions at once — and the reinforcement is forged into the body per MSS SP-97, making a code-compliant branch on the elbow itself: the classic seat for a thermowell looking straight down the run axis, and for the drains and vents a bend's low and high points invite. The branch end comes all three ways — butt-weld, socket-weld or threaded per ASME B16.11 — in NPS ¼″ to 12″, Classes 3000/6000 and STD/XS to 160/XXS, fitting 1.5D long-radius elbows as standard and 2D/3D bends to stated radius, in every material grade on this site: carbon steel, LTCS, the chrome-moly ladder, stainless, duplex and the nickel alloys. Each piece is laser-marked branch × elbow, class, grade and heat, certified to EN 10204 3.1/3.2. Dimension tables in the datasheet below. ISO 9001:2015, made in Mumbai, India — exported to 50+ countries.
MSS SP-97 · B16.11 EndsElbow Outlet · Thermowell Boss on BendBW / SW / Threaded — All Three EndsNPS ¼″–12″ · Class 3000 / 6000Fits 1.5D LR · 2D / 3D to Stated RadiusCarbon Steel to Nickel AlloysEN 10204 3.1 / 3.2 · ISO 9001:2015
304 Stainless Elbolets, ¾″ × 4″ Class 3000 — the Compound Saddle That Seats on an Elbow's Back
What is an Elbolet?
The branch that lives on the bend. An elbolet (also written elbow outlet) is a forged, integrally reinforced branch outlet fitting welded onto the outside radius — the back — of a 90° elbow, where a conventional olet cannot sit. Its base follows the bend's compound curvature; its branch end is butt-weld, socket-weld or threaded per ASME B16.11; reinforcement is forged in per MSS SP-97. The classic duty is the thermowell that looks straight down the run axis, plus drains and vents at the bend. We forge them NPS ¼″–12″, Classes 3000/6000 and STD/XS to 160/XXS, for 1.5D and 2D/3D elbows, in every grade from A105 to the nickel alloys, laser-marked and certified to EN 10204 3.1/3.2.
Also searched as: elbow outlet, olet on elbow, thermowell boss on bend, elbolet BW/SW/THD, MSS SP-97 elbow outlet — all this page's product. Related pages: the weldolet and sockolet (the straight-run siblings, both live), the flangeolet, and the material pages behind every grade we forge: carbon steel, alloy steel, stainless, duplex, Monel, Inconel and Hastelloy.
Why Branch on an Elbow — the Thermowell Story
Connection at the Bend
Why the Elbow Is the Right Place
Thermowell
The well enters through the elbow's back and points along the run axis — deep immersion into the oncoming, well-mixed flow, without the vortex-shedding loads of a well cantilevered across a straight pipe
Drain
A bend's outside radius is the system's true low point when the leg drops — the drain sits where the liquid actually collects
Vent
The same geometry inverted — the crown of a rising bend is where gas pockets
Instrument tapping
When the straight runs are crowded with supports and other taps, the elbow's back is honest real estate
The elbolet is what makes these code-compliant branches rather than improvised cuts into a stressed bend — the compound saddle closes the geometry, and MSS SP-97's forged-in reinforcement does the rest.
Curved in two directions at once, machined to the stated elbow size and radius — a properly cut saddle sits metal-to-metal on the bend's back without rocking, so the groove weld starts from a fit, not from grinding.
All Three Ends, One Fitting
Butt-weld, socket-weld or threaded — the only olet routinely supplied in every end type, because thermowell, drain and vent practice spans all three habits.
One Branch, Any Elbow
The same ¾″ top over saddles for 4″, 6″ and 12″ elbows — the trio photographed below, three consecutive heats across one order: the branch names the bore, the elbow names the saddle.
Reinforcement Forged In
MSS SP-97's compensation in the body profile — no pad bent over a bend, no field-fabricated reinforcement on a stressed component, every surface inspectable.
Specification Notes — Getting Elbolets Right
Three honest notes.State the elbow's radius, not just its size: a saddle cut for a 6″ long-radius elbow rocks on a 6″ 3D bend — branch × elbow × radius on the enquiry saves a fit-up problem at the spool shop. Some line classes restrict attachments on bends: an elbow is a stressed, thinned component, and critical-service specifications may ask for the branch calculation explicitly or prefer a weldolet on the adjacent straight with a longer well — the designer's word decides. And the end type carries its own rules: socket ends keep the root-gap habit the sockolet page explains, threaded ends live by the thread engagement, butt-weld ends by the bevel — name the end with the sizes.
How Our Elbolets Are Manufactured
1
Material — certified forgings in the ordered grade, heat treated as the grade demands — normalised LF2, N&T chrome-moly, solution-annealed stainless and duplex — furnace records retained; heat-number transfer at the first operation.
2
Body machining — the MSS SP-97 profile turned to the tabulated dimensions for the branch size.
3
Compound saddle — the base machined to the stated elbow size and radius — the two-way curve that is this fitting's whole identity — and checked against template.
4
End preparation — bevel for butt-weld, B16.11 socket bored square and true, or NPT/BSPT thread cut and gauged — per the ordered end type.
5
Testing & marking — PMI on alloy grades, MPI/DPT/UT to the ordered scope, then laser marking: grade, branch × elbow, class, heat number.
6
Certification & packing — EN 10204 3.1 MTC (3.2 witnessed on request); saddles and ends protected, packed sea-worthy.
Where Elbolets Are Used
Everywhere temperature is measured at a bend: refinery and petrochemical units instrument their transfer lines and reactor circuits through elbow-mounted thermowells; power stations put them on steam bends in the chrome-moly grades; and process plants of every kind use the elbow's low and high points for the drains and vents the P&ID calls for. Production pieces below — the marking on each is real:
One Branch, Three Elbows — ¾″ × 4″ / 6″ / 12″, Heats TF1109–TF1111
Elbolet Dimensions — How the Tables Work
The elbolet's geometry splits in two, and the datasheet handles it honestly. The body dimensions are fixed by the branch size and tabulated per class — Class 3000 / STD-XS in 15 sizes from ¼″ to 12″, Class 6000 / Sch 160-XXS in 7 sizes to 1½″. The saddle and installed length, though, depend on the elbow underneath: the base follows a 1.5×NPS long-radius back or a 2D/3D bend's, and the derived length runs per the datasheet's relation with its 1.6 mm root-gap allowance. Download the datasheet (PDF) for both tables and the governing relations — and for stack-ups on a specific bend, state branch × elbow × radius and we confirm installed dimensions on the order.
Class 3000 · STD / XS
Class 6000 · Sch 160 / XXS
Branch sizes
¼″ – 12″ (15 sizes)
¼″ – 1½″ (7 sizes)
End types
Threaded & SW (Class 3000); BW (STD/XS)
Threaded & SW (Class 6000); BW (160/XXS)
Fits elbows
90° long-radius 1.5D as standard; 2D / 3D bends to stated radius; short-radius and reducing elbows to drawing
How to Specify & Order an Elbolet
Seven elements — the elbow's radius is the one people forget:
1
Branch size — e.g. ¾″.
2
Elbow size and radius — e.g. 6″ long-radius 1.5D, or the 2D/3D bend your line uses.
3
Branch end type — butt-weld, socket-weld or threaded (NPT/BSPT).
4
Class or schedule — 3000/6000 for SW and threaded; STD/XS or 160/XXS for butt-weld.
5
Material grade, exactly — A105, A350 LF2, A182 F304 dual-certified, F22... as your specification writes it.
6
Certification & NDT — EN 10204 3.1 (our standard) / 3.2 witnessed; MPI, DPT, UT or NACE scope if extended.
7
Quantity & destination — to sales@tescosteel.com or the inquiry form; attach the instrument datasheet if the branch carries a thermowell.
Example: “Elbolet, ¾″ branch × 6″ LR 1.5D elbow, socket-weld end, Class 3000, ASTM A182 F304/304L dual-certified, B31.3, EN 10204 3.1 — 6 pieces.” Quotations normally within 24 hours with price, unit weights and delivery.
Elbolets — Frequently Asked Questions
What is an elbolet (elbow outlet)?
An elbolet is a forged, integrally reinforced branch outlet fitting made for the one place a normal olet cannot sit: the outside radius — the back — of a 90° elbow. Its base is contoured to the elbow's compound curvature, a saddle curved in two directions at once, and it is welded onto the bend to give a full-strength branch connection there, most often for a thermowell, an instrument tapping, a drain or a vent. The branch end comes three ways — butt-weld bevel, socket per ASME B16.11, or tapered thread — and the reinforcement is forged into the body per MSS SP-97, so no pad is needed on the bend. We forge elbolets in NPS ¼" to 12" for butt-weld duty and ¼" to 1½" in the heavy-wall classes, in every material grade on this site, each laser-marked and certified to EN 10204 3.1/3.2.
Why put a branch on an elbow at all — the thermowell story?
Because the elbow is the one fitting that lets an instrument look straight down the pipe. A thermowell inserted through the back of a 90° elbow points along the run's axis, into the oncoming flow — deep immersion in the fastest, best-mixed stream, without the bending loads a well cantilevered across a straight pipe collects from vortex shedding. Temperature measurement practice has used the location for a century, which is why the elbolet exists. The same geometry serves other jobs: a drain at the true low point an elbow creates, a vent at its high point, and instrument tappings where the straight runs are already crowded. The elbolet's contoured saddle is what makes all of this a code-compliant branch rather than an improvised cut into a bend — the reinforcement is forged in, exactly as on the rest of the olet family.
What branch ends do elbolets come with?
All three — the elbolet is the one member of the olet family routinely supplied with every end type, because its duties span every small-bore habit. Butt-weld: the branch end is bevelled and the connection is a full-penetration butt weld, the choice for process-rated nozzles and larger branches up to NPS 12. Socket-weld: the end carries a B16.11 socket — square-cut pipe in, back off for the root gap, fillet-weld — the standard for welded thermowell and instrument work. Threaded: NPT (or BSPT on request), for wells and fittings that must screw in and come out by hand, which many thermowell designs do. The end type travels with class and schedule: socket and threaded ends are class-rated 3000 or 6000, butt-weld ends are schedule-matched STD/XS or 160/XXS. State the end with the sizes and the rest of the specification falls into place.
What standards cover elbolets?
The same pair that governs the whole olet family, with the elbow adding its own geometry. MSS SP-97 — Integrally Reinforced Forged Branch Outlet Fittings — owns the body: reinforcement, pressure-temperature basis, marking, materials cross-references. ASME B16.11 owns the socket and thread dimensions on those end types, so branch pipe and wells fit an elbolet exactly as they fit a coupling. The elbow underneath is a B16.9 fitting — long-radius 1.5D as the default, 2D and 3D bends where the line uses them — and the saddle is machined to the stated elbow size and radius. Branch reinforcement logic on the line is the piping code's, B31.3 or B31.1. Materials certify to their own standards — A105, A350 LF2, A182, B564 — so the certificate reads like a forging certificate, joined by the geometry the marking spells out: the pieces photographed here read '3/4" X 4" #3000' and so on, branch × elbow, class, heat.
What sizes and classes do elbolets come in?
Branch sizes run NPS ¼" through 12" for butt-weld STD/XS duty, and ¼" through 1½" where the heavy walls live — Sch 160 and XXS butt-weld, or Class 6000 socket and threaded ends; Class 3000 covers the standard socket and threaded range. In practice the order book is dominated by small branches on a spread of elbow sizes — the trio photographed on this page is exactly that: one ¾" branch machined for 4", 6" and 12" elbows, three different saddles under an identical top. That is the elbolet's sizing rule in one image: the branch names the bore and end type, but the elbow names the saddle, so an enquiry states branch × elbow size — and the elbow's radius, since a 1.5D long-radius back curves differently from a 3D bend's. The datasheet's tables carry the tabulated dimensions per branch size with the saddle geometry derived from the elbow.
Which elbows does an elbolet fit — and why must I state the radius?
Standard production fits 90° long-radius elbows — the 1.5D bend that dominates process piping — and we machine for 2D and 3D bends against a stated radius. The reason the radius matters is the saddle: an elbolet's base is curved in two directions, following the elbow's surface both around its circumference and along its sweep, and that compound curvature changes with the bend radius. A saddle cut for a 6" long-radius elbow will rock on a 6" 3D bend — same pipe size, different back. So the enquiry states three things about the geometry: branch size, elbow nominal size, and elbow radius (1.5D unless you say otherwise). Short-radius elbows and reducing elbows are handled against drawing. It is one line of information at enquiry time that saves a fit-up problem at the spool shop — the same run-range discipline the weldolet page describes, with the elbow's extra curve added.
What materials are elbolets available in?
Every grade this site forges. Carbon steel A105 and low-temperature A350 LF2 for the general and cold benches; chrome-moly A182 F11, F22, F5, F9 and F91 where the elbows sit in steam and hot hydrogen circuits — a thermowell boss on a hot reheat bend is classic elbolet work; stainless F304/F304L and F316/F316L with dual certification where heats qualify, plus stabilised F321 and F347 — the pieces photographed on this page are 304, laser-marked for a process order; duplex F51/F53/F55 for chloride duty; and the nickel bench — Monel, Inconel, Incoloy, Hastelloy — with copper-nickel and titanium against enquiry. The fitting follows the elbow's metallurgy, matching grade for grade, and the material pages across this site carry each grade's story. Chemistry per heat, PMI on alloy grades, EN 10204 3.1/3.2 on every lot.
How is an elbolet installed?
Like its siblings, with the bend adding one discipline: position. The location on the elbow's back is marked out — for a thermowell, centred so the well's axis runs along the downstream pipe's centreline — the opening is cut, and the saddle is offered up; a properly machined compound saddle should sit metal-to-metal without rocking, and if it rocks, the elbow radius on the order was wrong, not the welder. The base weld is a full-penetration groove weld around the saddle, exactly as on a weldolet. The branch connection then follows its end type: bevelled ends take a butt weld; socket ends take the B16.11 habit — insert square-cut pipe, back off roughly 1.6 mm for the root gap, fillet-weld; threaded ends are made up with the well or fitting they carry. Welding discipline follows the material — preheat and PWHT on chrome-moly, purge and low-carbon filler on stainless — and NDT of the base weld follows the line's specification.
Elbolet or weldolet — when does the bend need its own fitting?
Whenever the connection must live on the elbow itself. A weldolet's saddle is curved in one direction, to sit on a straight run — set it on a bend and it touches at points, not along its edge, and the groove weld starts from a gap. The elbolet's compound saddle exists to close exactly that gap. The practical division: branches that can sit on straight pipe upstream or downstream of the bend take the weldolet or sockolet, which are simpler and cheaper — their pages are live on this site; connections that must be at the bend — thermowells looking down the run axis, drains at an elbow's low point, vents at its crown — take the elbolet. One caution runs the other way: an elbow is a stressed, thinned component, and some critical-service specifications restrict attachments on bends or ask for the branch calculation explicitly — where your line class does, the designer's word decides, and the honest alternative is a weldolet on the adjacent straight with a longer thermowell.
Is 'Elbolet' a brand name?
By origin, yes — Elbolet belongs to the same family of Bonney Forge trademarks as Weldolet and Sockolet, and like them it long ago became the word the piping trade actually uses, on requisitions, isometrics and shop floors everywhere. This page uses it in that ordinary generic sense; the descriptive term is elbow outlet. What we manufacture and certify are integrally reinforced forged branch outlet fittings to MSS SP-97, contoured for 90° elbows, with socket and threaded ends dimensioned to ASME B16.11 — the wording our certificates carry, dimensionally and functionally interchangeable with any outlet made to the same standards. If your documents write 'elbow outlet', 'olet on elbow' or 'thermowell boss on bend', they mean this product; name the standards and the paperwork follows.
What is marked on each elbolet?
Manufacturer, material grade, branch × elbow size, class or schedule, and heat number — laser-marked on the machined body. The production pieces photographed on this page read exactly that way: '304 ELBOLET 3/4" X 4" #3000' with heat TF1109, its 6"-elbow twin marked TF1110 and the 12" one TF1111 — three consecutive heats across one order, each traceable to its own EN 10204 certificate. That branch-times-elbow convention in the marking is worth noticing: it is the fitting's whole geometry in one line, and it is what stores check against the isometric before a spool goes to the shop. PMI confirms alloy grades match the mark before dispatch, and project-specific marking — tag numbers, PO references — is applied to order and recorded on the documents.
What testing and certification come with elbolets?
The forging's full paper trail. Chemistry and mechanicals per heat on the EN 10204 3.1 MTC — 3.2 witnessed on request — with heat-treatment condition and furnace records where the grade demands them: normalised LF2, N&T chrome-moly, solution-annealed stainless and duplex. PMI verifies every alloy piece. NDT to the ordered scope: MPI or DPT of the machined saddle and end, UT of the forging where specified, hardness testing for sour service, with NACE MR0175 / ISO 15156 compliance available on request. Dimensional inspection checks the tabulated dimensions against the datasheet and — the elbolet's own item — the saddle template against the stated elbow size and radius, because the compound curve is the fitting. Third-party witness or review is routine on project orders; state the agency and scope on the enquiry.
Where can I find elbolet dimensions?
In the datasheet on this page — a two-page PDF with the dimension tables for both duty levels: Class 3000 / STD-XS in 15 branch sizes from ¼" to 12", and Class 6000 / Sch 160-XXS in 7 sizes from ¼" to 1½", each tabulating the fixed body dimensions per branch size. The elbolet's geometry has a wrinkle the tables handle honestly: the body's C and D dimensions are fixed by the branch, but the saddle and the installed height depend on the elbow underneath — the datasheet gives the governing relations, including the derived length formula with its 1.6 mm root-gap allowance, rather than pretending one number fits every bend. For stack-up calculations on a specific elbow, state branch × elbow × radius and we confirm installed dimensions on the order — non-standard heights and short-radius or reducing bends are machined to drawing.
What details are needed to get an accurate elbolet quotation?
Seven elements plus commercial terms: (1) branch size — e.g. ¾"; (2) elbow nominal size and radius — 4" long-radius 1.5D, or the 2D/3D bend your line uses; (3) branch end type — butt-weld, socket-weld or threaded, with thread form where it matters; (4) class or schedule — 3000/6000 for socket and threaded ends, STD/XS or 160/XXS for butt-weld; (5) material grade, exactly as your specification writes it; (6) certification and NDT — EN 10204 3.1 (our standard) or 3.2 witnessed, plus MPI/DPT/UT or NACE scope where extended; (7) quantity and destination. If the branch carries a thermowell, the well's process connection tells us the end type in one line — attach the instrument datasheet if it is handy. Quotations normally return within 24 hours with price, unit weights and delivery; common stainless and carbon steel combinations usually quote from stock.
Who manufactures elbolets in India?
Tesco Steel & Engineering is an ISO 9001:2015 certified manufacturer based in Mumbai, India, forging integrally reinforced branch outlet fittings to MSS SP-97 contoured for 90° elbows — elbolets (elbow outlets) in NPS ¼" to 12", butt-weld, socket-weld and threaded ends per ASME B16.11, Classes 3000 and 6000, machined to the customer's elbow size and radius. Materials span our whole forge: carbon steel A105, LTCS A350 LF2, chrome-moly A182 F11 through F91, stainless 304/316/321/347 families, duplex F51/F53/F55 and the nickel alloys — with PMI verification, laser marking tying each piece to its heat, and EN 10204 3.1/3.2 certification on every lot. The same works supplies the complete olet family — weldolets, sockolets, threadolets, nipolets, latrolets, sweepolets and flangeolets — alongside the flange ranges this site is built around. Exported to more than 50 countries; datasheet with dimension tables downloadable on this page.
