Transformer Spade Terminals, Transformer Spade Connectors / Material and connection variants

C83300 Bronze Terminal Spades for Transformers

C83300 bronze terminal spades provide a straight stud-to-palm connection for pad-mounted transformers. Cable Glands India offers these CDA 833 copper-alloy components with NEMA-spaced mounting holes and a choice of natural or tin-plated finish. The threaded hub and machined palm are specified together to match the bushing stud and outgoing cable-lug arrangement.

Price on request. Quotation depends on the approved alloy, geometry, finish and order quantity.

Product overview

CDA 833 Material Selection

C83300 is a cast copper-base alloy with a relatively high copper proportion within the red-brass family. It is commonly purchased as C83300 bronze or contact metal. Use the formal UNS designation on the drawing because the commercial word bronze covers many compositions. Its copper, tin, zinc and lead limits distinguish it from C83600 and C84400. An approved C83300 terminal should not be replaced by another bronze grade without reviewing electrical, mechanical and procurement requirements.

Cast Body and Machined Contact Palm

The casting provides the connector body and hub, while machining establishes the functional faces, bore and bolt-hole locations. The transition between hub and palm needs sufficient material for the approved loading. Casting texture may remain on non-mating surfaces where the drawing permits it. Flatness, edge condition and surface cleanliness are controlled separately from the external appearance. Define acceptance criteria for casting discontinuities in areas that affect current flow or thread engagement.

Electrical Interface for Pad-Mounted Units

A C83300 spade can provide a common bolted node for compatible cable lugs within the transformer compartment. The design must coordinate cable routing, lug width, palm contact area and enclosure clearances. An eight-hole illustration does not establish eight independent circuits or a particular ampacity. Supply the equipment duty, conductor arrangement and bushing drawing so that the selected terminal can be assessed as part of the complete joint.

Key features

• UNS C83300 / CDA 833 material specification for traceable procurement.
• NEMA-spaced palm for compatible bolted terminal layouts.
• Natural and tin-plated finish options.
• Straight connection geometry for the specified transformer arrangement.
• Machined contact surfaces, bores and threads to an approved drawing.
• Configuration review for electrical OEMs, EPC contractors, power utilities and distributors.

NEMA palm and bolted contact interface

The palm provides the contact area between the transformer connector and the mating lug or busbar. Hole spacing supports interchangeability only when hole diameter, edge distance, palm thickness and terminal orientation also agree. Confirm access for sockets and spanners in the enclosure. A greater number of holes does not automatically permit a higher current or a larger number of independent outgoing circuits. The assembled connection and conductor arrangement govern the operating duty.

Natural metal and tin-plated contact surfaces

Natural finish retains the appearance of the selected base material. Tin plating provides a different surface condition for the specified joint design and handling environment. Specify preparation, coating thickness and coverage before manufacture. Threads may require allowance or masking to preserve fit after plating. Evaluate the complete joint when connecting dissimilar metals, including the conductor, lug, fasteners and environmental exposure. Do not assume that tin plating alone establishes aluminum-conductor compatibility.

Stud fit and dimensional control

The stud connection must match both the nominal size and the detailed thread designation. Pitch, class of fit, usable thread depth and entry chamfer affect assembly. Check shoulder contact and available engagement against the bushing drawing. Incorrect thread combinations can appear to start and still damage the mating terminal. Use the OEM installation procedure and specified tightening torque; neither the alloy name nor a catalog illustration defines a safe torque setting.

Technical specifications

Material composition and international designations

Composition values are weight percentages where shown. The governing purchase specification and material certificate determine acceptance, including any residual-element limits not reproduced here.

Product variants

Industrial applications

C83300 Bronze Terminal Spades for Transformers are intended for the terminal connection zone of pad-mounted transformers. They can form part of an OEM bushing-to-lug or stud-to-palm assembly, subject to the transformer design. Utilities use approved connector configurations for equipment replacement and maintenance programs. EPC contractors specify the terminal interface alongside cables, lugs, busbars and installation hardware. Distributors should identify the actual material and thread arrangement so that a visually similar part is not supplied as an unapproved replacement.

For retrofit work, check the existing terminal drawing, enclosure clearance and conductor approach before ordering. Confirm corrosion exposure, operating temperature and fault duty with the equipment owner. Installation and maintenance should follow the applicable equipment instructions with the system isolated and made safe.

Manufacturing process

1. Review the C83300 specification, casting drawing and inspection requirements.
2. Prepare the specified casting route and identify the alloy heat.
3. Cast the body with appropriate machining allowance and inspect critical areas.
4. Machine the hub, contact palm and NEMA-spaced holes to drawing.
5. Cut and gauge the specified stud thread, then deburr and clean.
6. Supply natural finish or apply the agreed tin coating and complete final checks.

Production release should connect the drawing revision to the material lot, machining setup and inspection plan. Changes to palm thickness, bore geometry or hole layout can affect both mechanical fit and the thermal performance of the assembled joint. Agree first-article checks for a new design before repeat quantities are released. Pack contact surfaces to limit damage during transport and keep natural and plated batches clearly identified.

Quality standards and documentation

NEMA spacing describes the mounting interface; it is not a standalone certification of the finished connector. Standards listed here are specification references to be agreed for the order. No universal UL listing, IEC approval, ISO certification or blanket environmental-compliance claim is implied for every custom variant. If regulated-substance requirements apply, identify the destination market and required declaration before selecting a lead-containing alloy.

Why choose Cable Glands India

This product range brings material selection, connection geometry and finish into one drawing-based inquiry. Buyers can compare bronze, copper, forged brass and cast brass versions within the same transformer terminal family. A clear specification helps procurement teams obtain comparable quotations and helps engineering teams separate material identity from assembly performance. State the required inspection records, marking and packaging at the quotation stage so the supply scope is reviewable before manufacture.

Questions and answers

How does C83300 differ from C83600?

They are different alloy grades with different composition limits. C83300 has a higher specified copper range. That difference alone does not establish the rating of a finished terminal; the approved assembly design remains controlling.

Are these connectors suitable for pad-mounted transformers?

They are intended for pad-mounted transformer terminal connections where the approved bushing, stud, palm, conductor and enclosure arrangement matches the connector drawing. Confirm electrical duty, clearances and mechanical loading with the transformer OEM before release.

Are the mounting holes NEMA spaced?

Yes. The palm uses a NEMA-spaced mounting arrangement. Specify the exact hole count, center-to-center dimensions, hole diameter and orientation on the order drawing; the phrase NEMA spaced alone is not a complete interface specification.

Can I order natural and tin-plated finishes?

Yes. Both natural metal and tin-plated finishes can be specified. State coating thickness, coverage, masking, contact-surface requirements and inspection criteria. Tin plating does not change the underlying alloy designation.

Which stud threads can be supplied?

The family includes nominal 3/8, 1/2, 3/4 and 1 inch stud interfaces, with UNC, UNF, UNEF or UNS forms where the drawing requires them. Confirm diameter, pitch, class, engagement length and thread direction; not every diameter uses every series as a standard combination.

What is the current rating?

There is no single current rating for all geometries. The assembled connection must be assessed for conductor size, contact area, temperature rise, installation torque and fault duty. Request the test requirements for your approved design instead of selecting by alloy or hole count alone.

Are installation bolts and washers included?

Specify the complete hardware bill of materials in the inquiry. Inclusion, bolt material, coating, washer arrangement and approved tightening torque must be confirmed for the supplied assembly.

Can a similar international alloy be substituted?

Use the specified grade and product form as the procurement baseline. A proposed substitute needs a comparison of chemistry, mechanical properties, conductivity, casting or wrought condition and the governing standard, followed by customer approval.

What information is needed for a quotation?

Send the drawing and revision, alloy, quantity, stud thread, palm dimensions, NEMA hole pattern, finish, inspection documents and delivery destination. Identify prototype quantities separately from repeat production requirements.

Related transformer terminals and connectors

• C84400 Bronze Spade Connectors
• C83600 Transformer Spade Terminals
• Copper ETP Transformer Spade Connectors
• C37700 Forged Brass Transformer Spades
• Transformer Spade Terminals from Brass Casting
• Bronze Stud Connectors for Transformers