Precision Shafts and Bushes

Vajra Techno machines precision shafts, bushes, pins, rollers, spacers and flanges to customer drawings at Dewas, Madhya Pradesh, in mild steel, stainless steel 304 and 316, grey cast iron, ductile iron and aluminium. Parts are inspected before dispatch and supplied pan-India.

Which parts are covered?

• Shafts — drive shafts, spindle shafts, stub shafts, splined and keyed shafts
• Bushes — plain bearing bushes, flanged bushes, wear bushes, guide bushes
• Pins and rollers — dowel pins, pivot pins, cam followers, conveyor rollers
• Spacers and shims — machined to thickness for assembly stack control
• Flanges — shaft flanges, pipe flanges, mounting flanges
• Bearing housings — machined for bearing seat fit and mounting relationship

Which operations are in-house?

Milling operations — keyways, flats, cross-holes, spanner flats, face features, bolt-hole patterns and end-face machining — run in-house on our vertical and horizontal machining centres.

Turning, cylindrical grinding, centreless grinding and heat treatment are quoted on request as part of a finished-part price. This is the single most important thing to settle on a shaft enquiry, because shaft tolerance is usually set by the turning and grinding route rather than by the milled features. State your requirement and the full process route is confirmed in writing before quoting.

What fits and tolerances are held?

Shaft and bush work is normally called by ISO fit rather than by absolute dimension. Parts are machined to the fit class stated on your drawing, and the class we accept is confirmed against the feature at quotation. Send the print with the fit callouts marked and you get a written yes or no on each one.

Where a print calls a running fit and a press fit on the same part, both are quoted against the same datum so the fits are consistent in assembly. Per-material figures are tabulated on the capabilities page.

How are concentricity and runout controlled?

A shaft that is on-diameter but out of runout will not run. Concentricity between diameters and total runout to the datum axis are therefore controlled features, checked on every first article and at agreed frequency in production.

Runout and concentricity are committed against the callout on your drawing, since the achievable band depends on the length-to-diameter ratio, the number of diameters and the finishing route. Long slender shafts are supported during machining to control deflection; the ratio at which support becomes necessary is a process decision taken at planning stage, before the first cut.

What surface finish is achieved on running surfaces?

Running and sealing surfaces are the features where finish determines service life, so finish is committed per feature against your drawing rather than as one blanket figure. Where a shaft runs against a lip seal, state the seal running-surface requirement explicitly on the drawing — it is usually tighter than the general finish callout, and a shaft that meets the general callout can still chew a seal.

Are parts hardened?

Heat treatment — induction hardening, through hardening, case carburising, nitriding — is arranged on request. Where hardening is applied, the machining sequence is planned so that finishing follows heat treatment on any feature that must hold tolerance, because distortion in treatment will otherwise put a finished dimension out and the part is scrap.

Hardness verification and its report are arranged on request. State the required hardness, the test location on the part and the acceptance range on the drawing so it is verified against a defined condition.

Are bushes supplied in bronze or self-lubricating grades?

The standard material list is grey cast iron, ductile iron, aluminium, mild steel and stainless steel 304 and 316. Bronze, gunmetal and sintered self-lubricating bush materials are quoted case by case — send the grade with the drawing and you get a yes or no before you spend time on the enquiry.

What quantities and lead times apply?

Prototype and single-piece shafts are quoted alongside repeat batches. Typical batch size and lead time by part family are on the capabilities page. Repeat schedules against a standing process plan run to shorter lead times than first-off work, because process planning and first-article approval are already complete.

How is the work inspected?

First article is inspected against every dimension on the print, with a written report before batch release. Production checks cover diameters, fits, runout and length dimensions at agreed frequency. Inspection equipment held in-house and what each verifies are listed on the capabilities page.

How are shafts packed for pan-India dispatch?

Ground and running surfaces are coated with a rust preventive and individually sleeved so that shafts do not contact each other in transit. Long shafts are crated to prevent bending. Dispatch is by road from Dewas, Madhya Pradesh, anywhere in India.

How do I get shafts or bushes quoted?

Send the dimensioned print in DWG, DXF or PDF with material grade, hardness requirement, fit classes, batch quantity and required date, via the RFQ form or to vajratechnoinc@gmail.com.