A groove that looks right on the drawing can still leak. We see it regularly: a part arrives with a clean bore, sharp corners and a bright finish, then fails leak testing because the groove was cut to the wrong depth or left with tool marks running across the sealing face. O-ring groove machining looks simple, but it is one of the few features where a few ten-thousandths of an inch decide whether the seal holds. This guide covers how to read AS568 dimensions, where tolerances

A revision letter on a print looks like a small detail until a job runs against the wrong one. In our shop, a single mismatched revision can mean a scrapped blank, a rerun program, and a customer asking why a part that passed last quarter now fails. Drawing revision control for machining is the discipline that prevents that outcome. It depends less on expensive software than on a few rules applied every time a print changes. This guide covers the rules we use at Summit City P

A keyway cut a few tenths too wide will rock under load, and the shaft will start to fret long before the drawing says it should. Keyway machining looks like the simplest feature on a shaft, which is why it so often gets the least engineering attention. Splines and broached features get the same treatment, even though they are where tolerance stack-ups and tool wear show up first. This guide covers how each feature gets made, where each method breaks down, and which shaft fea

Outside processing is where many precision machined parts quietly lose their schedule. A shop can hold a bore to tight tolerance all week, then watch a heat treat batch come back with distortion that pushes a critical diameter out of spec. Heat treat, plating, and grinding vendors sit outside your walls, but their results land on your part number and your on-time record. This guide covers the decisions that matter most, from callouts on the print to the vendor scorecard you r

A part can measure perfect on the inspection bench and still refuse to go together on the assembly line. In our experience, that gap usually comes from tolerances that were each reasonable on their own drawing but were never added up across the full assembly. Tolerance stack-up analysis is the calculation that catches this before the first part is cut. This guide explains how the math works, which method to request, and what a buyer should expect from a machining partner who

Most hydraulic manifold blocks fail in the same few places: a cross-drilled intersection that was never fully deburred, a sealing face that looks flat under a loupe but weeps under pressure, or a port that sits a few thousandths off position and forces a hose to twist. Hydraulic manifold machining looks simple on a drawing with a block of steel or aluminum, a few dozen holes, and a handful of threads. In practice, the work is dominated by intersections, tolerances that stack

Thin wall machining is where precision manufacturing earns its reputation, or loses it. The moment a wall-to-height ratio pushes past roughly 1:10, you stop treating that workpiece as a rigid body and start treating it as a spring. Radial cutting forces physically push the wall away from the tool, the material springs back once the cutter passes, and you end up with uneven wall thickness, dimensional drift, and chatter marks that look like a washboard. For industrial manufact

A rejected shipment, a failed audit, a costly recall: all three often trace back to the same root cause, a part that could not be identified at the moment it mattered most. Part marking in precision machining is not a finishing detail or a box to check before shipping. It is the backbone of every traceability system your customers depend on, and when it fails, it fails loudly. Whether you supply automotive Tier 1 assemblies, aerospace sub-assemblies, or complex industrial too

A bearing bore that is off by 0.015 mm in the wrong direction will either spin freely in its housing or seize during assembly. Neither outcome is acceptable in a production environment. Bearing bore machining sits at the intersection of dimensional control, surface texture, and fit selection, and mistakes in any one of those three areas ripple downstream into premature bearing failure, warranty claims, or scrapped assemblies. This guide lays out exactly what tolerances, fits,

Surface finish in precision machining is one of the most under-specified and over-assumed characteristics on an engineering drawing. A part can hit every dimensional tolerance and still fail in service because nobody nailed down a roughness requirement. In high-stakes applications, the difference between a Ra 1.6 µm and a Ra 3.2 µm surface on a sealing face is not a rounding error. It is the difference between a component that works and one that leaks, wears prematurely, or g

Most manufacturers treat calibration as a compliance checkbox. They send instruments out on a schedule, get a certificate back, and file it. That approach works fine until a nonconformance lands on your desk and every measurement trace in your PPAP package points to a lab you cannot actually verify. MetroLab calibration exists because Summit City Precision Machining built an in-house metrology division specifically to close that gap, connecting the measurement chain directly

Choosing a contract machining supplier without a structured evaluation is one of the most expensive mistakes a procurement or engineering team can make. You discover the problem after the first article fails, after a delivery slips three weeks, or after a PPAP submission comes back incomplete with your OEM launch date still on the calendar. Evaluating a CNC machine shop before you commit a real order takes time upfront, but it eliminates the kind of supplier failures that cos

Most quoting confusion between contract machining customers and their shops comes from one source: the buyer thinks they are ordering the same service at a lower volume, but the shop is actually running a completely different process. Production machining and prototype machining share the same machines and the same tolerances, but they operate on fundamentally different cost logic, process priorities, and quality documentation requirements. If you do not understand which mode

Most machine shops can hold a tight tolerance on a good day. Fewer can hold that tolerance consistently, document every step from raw stock to shipped part, and hand you a compliant First Article Inspection package that a prime contractor will actually accept. That gap is exactly what separates a capable aerospace precision machining supplier from one that will cost you a program. Whether you are sourcing close-tolerance structural brackets, engine-adjacent components, or fli

When a critical component fails dimensional inspection on a Friday afternoon and your production line runs Monday morning, the question of whether your machining supplier is 10 miles away or 1,000 miles away stops being theoretical. Local precision machining is not a nostalgic preference for old-school buyers. It is a concrete operational advantage that shows up in lead times, communication quality, first-article iteration speed, and the kind of collaborative problem-solving

Automotive precision machining is unforgiving. A single out-of-tolerance bore, a missing PPAP element, or a delayed shipment can stall an entire assembly line. For industrial manufacturers sourcing machined components, the question is never just "can the shop hold the tolerance?" It is also "can they document it, back it up with traceable inspection data, and deliver on schedule?" Summit City Precision Machining (SCPM) in Fort Wayne, Indiana answers all three with a structure

Precision shops that cut tool steel for the first time without adjusting their process quickly discover why it has a reputation for destroying tooling and blowing tolerances. Tool steel machining is not simply a harder version of mild steel work. The carbide content, heat-treat state, and grade selection each change what the machine, the tooling, and the programmer need to do. For companies building gauges, fixtures, and production tooling, getting those choices right is the

If you have ever received a precision machined component that passed dimensional inspection but still would not assemble correctly, you have experienced what happens when GD&T machining callouts are missing, misread, or ignored. Geometric dimensioning and tolerancing is not paperwork formality. It is the language your drawing uses to tell a machinist, a fixture builder, and a CMM programmer exactly what functional variation is acceptable and what will cause failure downstream

When a critical machine goes down and the OEM stopped making the part a decade ago, you have two choices: scrap a capital asset that still has productive years left, or call a precision machining shop that knows how to reverse engineer and manufacture replacement machined parts from scratch. For industrial manufacturers running legacy equipment, that second option is not a last resort. It is a deliberate maintenance strategy, and the shops that execute it well use the same 5-

When a new aerospace or precision component moves from the drawing to the production floor, the first article inspection is not a formality. It is the documented proof that your manufacturing process can actually produce what the design requires. The problem most shops face is not the inspection itself. It is the time it takes, the risk of a rejected FAIR package, and the pressure to not let quality bottlenecks kill a delivery promise. CMM programming done correctly addresses