CNC spindle with an end mill cutting under flood coolant
PART‑MOD.COM A Covenant MFG service
Caleb@part-mod.com
Vendor stock, modified to print

Custom modifications to off-the-shelf parts

Send the vendor part number and a marked-up drawing or STEP file. We source the stock part (or receive yours!), make the modification, and ship it.

Instant estimate from $240 per line item, plus material · Firm quotes by email · Files stay confidential
Vendors
McMaster‑Carr, Swagelok, Digi‑Key, others
Email us
NDA
Send yours over and we will sign it
A gear and a gear rack marked up with modification callouts: increase bore to M8 H7, tap existing hole locations to 1/4-20 (x3), and cut to 5.875 inch length.

Stock part almost what you need? Don't have it made from scratch — let us modify it for you.

01

Drilling & tapping

Cross-holes, vent holes, tapped bosses and set-screw holes located to your dimensions.

02

Cut to length

Shafts, tubing, extrusion and standoffs shortened and faced square, ends deburred.

03

Milling flats & slots

Wrench flats, clearance pockets, keyway slots and relief cuts on round or square stock.

04

Threading

Added external threads, thread extensions, re-threading and pipe-thread conversions.

05

Counterbores

Existing holes opened, counterbored or countersunk so hardware sits flush.

06

Custom features to print

If the feature you need is not on this list, we cut it to your specifications — dimensioned off your drawing or model.

Outside this list — welding, plating, heat treat, full custom parts — say so in your email and we will tell you yes or no in the reply, not three emails later.

Two polished stainless steel ring housings: the stock part on the right, and the same part on the left after a radial hole pattern was drilled through the wall.
From the shop · Drilling

Stock housing in. Drilled to print out.

An existing stainless housing (right) and the same part after custom modification (left).

Process

Quote to shipment
  1. 1

    You email the spec

    Part number, quantity, and a STEP file or marked-up PDF to Caleb@part-mod.com. Use the instant estimate first for a ballpark.

  2. 2

    We quote it

    A firm price, plus any question we have about the print.

  3. 3

    We buy and machine

    Stock ordered the day you approve, then modified in-house. Or ship us parts you already have and we skip straight to the machining.

  4. 4

    Shipped with CofC

    Parts arrive with a Certificate of Conformance.

Capabilities & terms

Scheduling

If you have a date to hit, say so in your email and the reply will tell you what is actually possible for the work and the material.

Tolerances

Modified features are held to the tolerances on your print. Call out anything tighter than the vendor's stock tolerance explicitly — we will confirm it before quoting rather than assume it.

Confidentiality

Files you send are used to quote and machine your parts, nothing else. If you need an NDA in place before you send anything, send yours over and we will sign it.

PART‑MOD.COM Estimates are indicative and subject to engineering review. A service of Covenant MFG · © 2026