Standard Parts in Tool Manufacture – Knobs, Levers and Handles

Standard parts are indispensable building blocks in tool and mold manufacture. They are the foundation for the production of precise molds, tools and devices. Standard parts are standard components and are used to increase efficiency, reduce costs and ensure the interoperability of manufacturing processes. This article describes how standard parts are defined, what distinguishes them from standard parts, and where standard parts such as knobs, levers, and handles are used.

Definition - What are standard parts?

Standard parts are standardized machine elements that are used in mechanical engineering, both in tool making and in mold making. Especially in tool making, standard parts are an essential component for ensuring ever shorter development and delivery times.

A distinction must be made between standard parts and standard components. Standard parts are standardized components that are regulated by official standards such as the DIN standards. All details of the standard part are described in the standard. Standard components are, for example: screws, washers, nuts, pipes, bearings of all kinds and seals.

Standard parts, on the other hand, are not subject to any specific standard. They are unified elements, which are prefabricated in different variants and sizes. Standard parts are mass-produced parts with the same design and properties. They are used so frequently that standardization of these parts is worthwhile. These can include non-standard screws, washers or molded parts, among many other parts. Standard parts are often used where parts are required in large quantities, but standardized parts cannot be used for design reasons.

Development of standard parts - tool making then and now

The development of standards is closely connected to the industrialization. Constantly growing production numbers led to a need for standardized components. This was the only way to ensure the efficiency and interchangeability of the components and simplify production. As a result, various companies began to develop their own factory standards as early as the 18th/19th century. Shortly afterwards, the first standardization organizations emerged, paving the way for the introduction of standard parts. However, standard parts were not sufficient for all industries: With the automotive industry, an industry with specific requirements developed in the 20th century. Standard parts could not always meet these requirements. We needed our own standards: these so-called company standards form the basis for standard parts. With the boom in the manufacturing industry in the post-war period, companies outside the automotive industry increasingly developed their own standards. Now, standard parts were widespread. And today, thanks to the introduction of CAD technologies, global supply chains and increasing digitalization, they can be produced even more precisely and efficiently.

Advantages of Standards

Standard parts are components that have generally been tried and tested for a long time (e.g. in terms of properties and shape, according to factory standards) and the function of which can therefore be guaranteed. As standardized parts, they are also quickly available and easily replaceable. This standardization makes it possible to use standard parts in a similar way to standard parts, since they are available in large quantities in the same form and properties. In terms of functionality and dimension, they are often equal or equivalent to standard parts, but since they are not subject to standardization, they have a very wide range of construction options. Without the complex standardization process, standard part manufacturers can thus respond more quickly to market needs. In most cases, even easily accessible CAD models are available for standard parts, since they are always the same components. Another advantage is that standard parts are produced in large quantities, which makes them relatively inexpensive.

If standard parts are ordered by customers on a recurring basis and in large quantities, they are often stored by the supplier or included in the standard range. They can therefore be delivered to the customer without much loss of time.

Standards for Mold and Tool Making

Most of the standards are used in tool and mold making. Tool making deals with the development and production of industrially used tools. These are, for example, specialized devices that are used primarily for mass production. CNC-controlled machine tools are often used in their production. Typical tools are, for example: Punching tools, cutting tools and bending tools. Mold making is a special area of tool making. Molds for various forming processes are manufactured here. Standard parts are used, for example, for die-casting.

The following components can, for example, be designed as standard parts

• Guide components: e.g. guide rods, serve to precisely align and guide moving parts.
• Centering bushings, centering pins: align tool halves with one another.
• Ejector pins: press formed parts from the mold.
• Sealing elements: prevent liquids such as a coolant from leaking from the tool.
• Tension and retaining elements: ensure the hold of the molding components also during the molding process.
• Various bolts (ball bolts, adjusting bolts): serve the precise movement and alignment of workpieces or components.
• Bore hole bushings: Bore hole bushings are used to ensure a precise tool guide during the processing of bore holes.
• Threaded inserts: A thread that is used in materials that cannot accommodate threads themselves.

Globalization is also increasing competitive pressure in tool making. New solutions must be developed ever more quickly, which forces companies to constantly increase efficiency. Standard parts in particular provide a reliable basis and considerable cost-saving potential.

Standard Parts at MISUMI

The MISUMI shop offers a variety of turn handles, hand wheels, knobs and clamping levers in various designs. Grips are available in a turnable and fixed position with various handle shapes. For example, there are various grips for hand wheels, such as rigid handles, cone handles or folding grips. In addition to many other items, the shop also offers solid disk handwheels or conventional hand wheels. In addition, knurled hand wheels made of aluminum and stainless steel are available. The levers and knobs are discussed in more detail below.

Tensioners and Clamping Levers

Clamping levers, tension levers, offset levers or fixed levers are offered.

With clamping levers, workpieces can be clamped and released quickly and easily. They consist of one grip and a clamping fixture. The clamping fixture is rotated, which either clamps or releases the lever:

• (1) Clamping lever with push button
• (2) Double-armed clamping levers
• (3) Adjustable clamping lever
• (4) Tension lever
• (5) Ratchet clamping lever
• (6) Cam lever/eccentric lever
• (7) Flat tension lever

* The clamping lever is always tightened by turning it (based on the thread turns). The figure only shows the repositioning of the lever or rather the lever arm.

• 1: The clamp is unlocked by pulling the lever upwards, thereby loosening the gearing between the clamping element and the control lever.
• 2: The unlocked lever can now be rotated in the desired direction.
• 3: After the lever is released, the return spring automatically locks the gearing between the clamping element and the control lever; the clamp is locked.

Standard features such as clamping and tension levers are offered in a wide variety of versions. In addition to the materials used and the possibility of a design with, for example, an internal or external thread, they differ among other things in their basic operating principle. A distinction is made between a clamping effect created by a thread or by an eccentric lever (misalignment). Another distinction is the possibility of adjusting the control lever itself. Rigid and adjustable clamping levers with external or internal threads are available, whereby adjustable clamping levers can also be equipped with a ratchet function, lock or torque limitation. Last but not least, various lever shapes such as L-shape, T-shape and Y-shape are available.

Offset levers, including eccentric levers, can be used to perform an offset movement. You have installed a cantilever pin and a thrust washer. By actuating the lever, the thrust washer tightens, the workpiece is fixed.

Locking screws, locking nuts and knobs

Locking screws, locking nuts and knobs are available in various designs.

Knobs are, for example, available in the following variants:

• (1) Mushroom handle
• (2) and (3) three-star and five-star grips
• (4) Knurled knobs
• (5) Cross handle

Knurled screws and knurled nuts have a head with mostly knurled sides and are designed for use without tools. Its grooved head circumference provides a good grip for tightening the screw or nut by hand.

Mushroom handles, in turn, are a possible option if the locking element is moved primarily by pull or pressure. Their ergonomic shape allows for quick operation. They are used, for example, for ball lock pins with a mushroom handle as a traction aid or as an actuating handle in emergency shut-off switches. The shape of the cross handles ensures a secure grip during operation. This means that high torques can be transmitted when space is limited. They are used, for example, in valves.

3-star grips have compact and efficient force transmission and are also suitable for tight spaces. 5-star grips are well suited for heavy machines and tension devices.

Grips

Grips are available in addition to other variants:

Overview of grips at MISUMI

• (1) Crank handle
• (2) Hand wheel with grip
• (3) Standard grip
• (4) Folding grip with spring
• (5) Rotary handle, foldable
• (6) Knurled hand wheel
• (7) Grip, foldable
• (8) Bow handle, retractable

Foldable grips or the retractable bow handle are suitable for situations where there is little space or a protruding handle would pose a safety problem, e.g. due to bumping or getting caught.

Grips on cranks provide optimum operability as they offer a comfortable and firm grip. They also improve force transmission through a more efficient and precise rotary motion. This can be advantageous, in particular for manual machines and tools.